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Groups > sci.electronics.equipment > #367 > unrolled thread
| Started by | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| First post | 2020-06-18 14:03 +0100 |
| Last post | 2020-06-24 20:03 +0000 |
| Articles | 20 on this page of 103 — 11 participants |
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Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 14:03 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 14:28 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-18 20:08 +0530
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 15:41 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-18 18:16 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-18 23:48 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-18 19:38 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-19 21:46 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-19 18:55 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-19 23:59 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-20 12:09 +0530
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-20 13:03 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-20 11:24 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-20 16:58 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-20 23:28 +0530
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-20 14:15 -0400
Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-06-20 23:54 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 05:10 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-26 11:27 -0400
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-27 06:40 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-27 09:55 -0400
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-29 02:59 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-29 10:54 -0400
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-30 03:28 +0000
Re: Error of % + digits? Jeroen Belleman <jeroen@nospam.please> - 2020-06-20 20:18 +0200
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-24 18:37 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 04:54 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-11 21:38 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-13 03:21 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:32 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-26 04:23 +0000
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-06-26 14:02 +0530
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-27 06:56 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-12 18:45 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-12 23:31 +0530
Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-07-12 20:21 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-13 10:23 +0530
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:36 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-13 20:57 +0530
Re: Error of % + digits? Jeroen Belleman <jeroen@nospam.please> - 2020-07-13 17:39 +0200
Re: Error of % + digits? Tom Gardner <spamjunk@blueyonder.co.uk> - 2020-07-13 21:04 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-20 21:35 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-20 21:36 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-07-21 12:05 +0530
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-31 23:53 +0100
Re: Error of % + digits? Pimpom <nobody@nowhere.com> - 2020-08-01 14:31 +0530
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:35 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-16 07:30 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:19 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-21 01:13 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-08-04 22:27 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-09-09 07:39 +0000
Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-17 12:15 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-28 19:02 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-13 13:38 +0100
Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-24 20:06 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-06-30 00:41 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-06-30 03:52 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-06-30 11:09 -0400
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-02 05:45 +0000
Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-02 07:03 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-02 10:41 -0400
Re: Error of % + digits? RheillyPhoull <Rheilly@bigslong.com> - 2020-07-03 09:20 +0800
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 20:09 +0100
Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 14:02 +0000
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 19:16 +0100
Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 20:26 +0000
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 21:44 +0100
Re: Separate amps jacks on multimeters Rich <rich@example.invalid> - 2020-07-17 22:37 +0000
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-18 00:11 +0100
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 18:07 -0400
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 23:31 +0100
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:10 -0400
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-18 00:18 +0100
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:30 -0400
Re: Separate amps jacks on multimeters "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-28 22:16 +0100
Re: Separate amps jacks on multimeters Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-22 04:24 +0000
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-22 12:28 -0400
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-17 19:25 -0400
Re: Separate amps jacks on multimeters Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-22 04:20 +0000
Re: Separate amps jacks on multimeters Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-22 12:23 -0400
Re: Error of % + digits? Jasen Betts <jasen@xnet.co.nz> - 2020-07-03 13:10 +0000
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-03 10:14 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 20:10 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 16:03 -0400
Re: Error of % + digits? Michael Terrell <terrell.michael.a@gmail.com> - 2020-07-16 13:13 -0700
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:02 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 23:29 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-24 22:09 +0100
Re: Error of % + digits? Rich <rich@example.invalid> - 2020-07-24 22:58 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-25 00:31 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:01 +0100
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:51 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-26 03:53 +0000
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:45 +0100
Re: Error of % + digits? Ralph Mowery <rmowery28146@earthlink.net> - 2020-07-16 15:53 -0400
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-16 18:46 +0100
Re: Error of % + digits? Michael Terrell <terrell.michael.a@gmail.com> - 2020-07-16 10:54 -0700
Re: Error of % + digits? "Commander Kinsey" <CFKinsey@military.org.jp> - 2020-07-17 00:15 +0100
Re: Error of % + digits? Cydrome Leader <presence@MUNGEpanix.com> - 2020-07-26 04:17 +0000
Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-30 07:59 +0000
Re: Error of % + digits? Dieter Michel <dmichel@prosound.de> - 2020-06-22 17:19 +0200
Re: Error of % + digits? Rich <rich@example.invalid> - 2020-06-24 20:03 +0000
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| From | Ralph Mowery <rmowery28146@earthlink.net> |
|---|---|
| Date | 2020-06-27 09:55 -0400 |
| Message-ID | <MPG.396119a6b66c2fa2989f38@news.east.earthlink.net> |
| In reply to | #395 |
In article <rd6pl5$42t$1@reader1.panix.com>, presence@MUNGEpanix.com says... > > What's the control loop if the PLC dies? How do people control temperatures > manually? Is there a foot pedal to stomp on to switch the heaters on and > off? > > > The process has two PLCs running all the time. There are two or more computers hooked to the data stream for the PLCs One PLC is the so called hot backup. It is not controlling, but if the primary one quits, the secondary one will either switch over automatically or it can be manually switched. One thermocouple is connected to the control loop. If that TC goes bad, there are other TCs that give the temperature readout and the operators switch the control screen for that temperature to manual and they have to keep an eye on it and manually enter on the computer keyboard what percentage of valve opening is needed to mantain the correct temperature.
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-06-29 02:59 +0000 |
| Message-ID | <rdblel$f8m$5@reader1.panix.com> |
| In reply to | #397 |
In sci.electronics.basics Ralph Mowery <rmowery28146@earthlink.net> wrote: > In article <rd6pl5$42t$1@reader1.panix.com>, presence@MUNGEpanix.com > says... >> >> What's the control loop if the PLC dies? How do people control temperatures >> manually? Is there a foot pedal to stomp on to switch the heaters on and >> off? >> >> >> > > The process has two PLCs running all the time. There are two or more > computers hooked to the data stream for the PLCs One PLC is the so > called hot backup. It is not controlling, but if the primary one quits, > the secondary one will either switch over automatically or it can be > manually switched. > > One thermocouple is connected to the control loop. If that TC goes bad, > there are other TCs that give the temperature readout and the operators > switch the control screen for that temperature to manual and they have > to keep an eye on it and manually enter on the computer keyboard what > percentage of valve opening is needed to mantain the correct > temperature. OK, so if a PLC croaks, the operators can switch to the redundant one. If a probe of whatever you have between it and the current loop or whatever it was fails, it's 100% manual control? How do you share the reading from one problem? Not trying to pole holes in theory here, just actually curious. One thing annoying about the probes I deal with is it seems no two are alike. Never been able to swap one for another, even with short leads, even with three lead compensation and get the same behavior on the same controller.
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| From | Ralph Mowery <rmowery28146@earthlink.net> |
|---|---|
| Date | 2020-06-29 10:54 -0400 |
| Message-ID | <MPG.3963ca91598a924989f3c@news.east.earthlink.net> |
| In reply to | #398 |
In article <rdblel$f8m$5@reader1.panix.com>, presence@MUNGEpanix.com says... > > OK, so if a PLC croaks, the operators can switch to the redundant one. If a > probe of whatever you have between it and the current loop or whatever it > was fails, it's 100% manual control? How do you share the reading from one > problem? Not trying to pole holes in theory here, just actually curious. > > One thing annoying about the probes I deal with is it seems no two are > alike. Never been able to swap one for another, even with short leads, even > with three lead compensation and get the same behavior on the same > controller. > > Here is sort of how it works. One PLC quits. The second PLC takes over automatically or can be switched manually at any time. A TC feeding the PLCs fails. An alarm is sounded as the PLC thinks the process has gone out of limits. The operator is at a computer (was running a graphics program on Win XP when I left) , He calls up the control screen and puts the control in manual and sets the signal to the valve to where it was before the device fails. There is a secondary temperature TC. The operator looks back in the history of the read outs and sees that the primary control TC was showing 300.2 deg C when the lab said the process was on target. At the same time the secondary TC was showing 301.6 deg C. So the operator now has the control in manual and adjusts the output of the contoler to try and keep the process at 301.6 deg C showing on the readiout now. When the bad TC is replaced and the process is checked out by the lab, The new setting may come back as 301.1 deg C. So that will be the new target. The vessels are large enough , around 10 feet tall and 5 feet in diameter so the temperature change takes a long time. The process is making polyester material. We put in a powder that looks like flour and a liquid Glycol. It is heated to about 300 deg C. There are 5 vessels in the process and it is continious. The powder and liquid are put in the first vessel and at the bottom is a pipe that conveys it to the next one. The process is repeated and small ammouts of other chemicals are added at each stage. It is extruded after the last vessel to what looks like string. It takes about 15 hours for the material to make it from start to finish. We make about 3000 pounds to 10,000 pounds of material each hour depending on the size of the process line. About 2 years ago the plant that had around 3000 people 20 years ago went out of business. Mostly because of other countries makeing the material much cheaper.
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-06-30 03:28 +0000 |
| Message-ID | <rdebgn$clp$1@reader1.panix.com> |
| In reply to | #399 |
In sci.electronics.equipment Ralph Mowery <rmowery28146@earthlink.net> wrote: > In article <rdblel$f8m$5@reader1.panix.com>, presence@MUNGEpanix.com > says... >> >> OK, so if a PLC croaks, the operators can switch to the redundant one. If a >> probe of whatever you have between it and the current loop or whatever it >> was fails, it's 100% manual control? How do you share the reading from one >> problem? Not trying to pole holes in theory here, just actually curious. >> >> One thing annoying about the probes I deal with is it seems no two are >> alike. Never been able to swap one for another, even with short leads, even >> with three lead compensation and get the same behavior on the same >> controller. >> >> > > Here is sort of how it works. One PLC quits. The second PLC takes over > automatically or can be switched manually at any time. > > > A TC feeding the PLCs fails. An alarm is sounded as the PLC thinks the > process has gone out of limits. The operator is at a computer (was > running a graphics program on Win XP when I left) , He calls up the > control screen and puts the control in manual and sets the signal to the > valve to where it was before the device fails. There is a secondary > temperature TC. The operator looks back in the history of the read outs > and sees that the primary control TC was showing 300.2 deg C when the > lab said the process was on target. At the same time the secondary TC > was showing 301.6 deg C. So the operator now has the control in manual > and adjusts the output of the contoler to try and keep the process at > 301.6 deg C showing on the readiout now. > > When the bad TC is replaced and the process is checked out by the lab, > The new setting may come back as 301.1 deg C. So that will be the new > target. > > The vessels are large enough , around 10 feet tall and 5 feet in > diameter so the temperature change takes a long time. > > The process is making polyester material. We put in a powder that looks > like flour and a liquid Glycol. It is heated to about 300 deg C. There > are 5 vessels in the process and it is continious. The powder and > liquid are put in the first vessel and at the bottom is a pipe that > conveys it to the next one. The process is repeated and small ammouts > of other chemicals are added at each stage. It is extruded after the > last vessel to what looks like string. > It takes about 15 hours for the material to make it from start to > finish. We make about 3000 pounds to 10,000 pounds of material each > hour depending on the size of the process line. > > About 2 years ago the plant that had around 3000 people 20 years ago > went out of business. Mostly because of other countries makeing the > material much cheaper. Interesting. I met an engineer who worked at Eastman decades ago. He had good stories about the complexity of starting a new production line of chemicals or plastics whatever they were making at the time. The amusing part was none of the people that designed the new systems could never get the first batches to work at full scale. They'd have an old timer operator figure it out for them after they all gave up. This process could take days. The final "say" on the machines I deal with are the colors of test strips that run through the entire process.
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| From | Jeroen Belleman <jeroen@nospam.please> |
|---|---|
| Date | 2020-06-20 20:18 +0200 |
| Message-ID | <rcljte$1or$1@gioia.aioe.org> |
| In reply to | #380 |
On 2020-06-20 17:58, Commander Kinsey wrote: [...] > > Showing those extra two numbers is pointless if they're wrong. All > that matters is how many volts difference between the actual voltage > and what is shown. Engineers distinguish between accuracy, a measure of how close a observed value is to the true value, and resolution, which is a measure of the device's ability to resolve small changes. Either specification is useful in its own right, and professional instrumentation will always have both specs. So even if the last digit or two of a measuring device are not accurate, they may still be useful. You may want to check audio ADCs and DACs for example, which have atrocious accuracy, but excellent resolution. An example of the opposite might be a voltage reference, which has excellent accuracy, but no resolution at all. Of course in general, there is a tendency of accurate instruments to have a better resolution too. Jeroen Belleman
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| From | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| Date | 2020-06-24 18:37 +0100 |
| Message-ID | <op.0mp8kenfwdg98l@glass> |
| In reply to | #383 |
On Sat, 20 Jun 2020 19:18:24 +0100, Jeroen Belleman <jeroen@nospam.please> wrote: > On 2020-06-20 17:58, Commander Kinsey wrote: > [...] >> >> Showing those extra two numbers is pointless if they're wrong. All >> that matters is how many volts difference between the actual voltage >> and what is shown. > > Engineers distinguish between accuracy, a measure of how close > a observed value is to the true value, and resolution, which > is a measure of the device's ability to resolve small changes. > Either specification is useful in its own right, and professional > instrumentation will always have both specs. So even if the > last digit or two of a measuring device are not accurate, they > may still be useful. I can see that, although when I've had an instrument with more digits than its accuracy, it usually has a fluctuation of its own (perhaps through interference from inadequate shielding), so I can't actually tell if the real value has changed. > You may want to check audio ADCs and DACs for example, which > have atrocious accuracy, but excellent resolution. An example > of the opposite might be a voltage reference, which has excellent > accuracy, but no resolution at all. > > Of course in general, there is a tendency of accurate instruments > to have a better resolution too.
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-06-26 04:54 +0000 |
| Message-ID | <rd3v1r$egj$1@reader1.panix.com> |
| In reply to | #380 |
In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote: > On Sat, 20 Jun 2020 16:24:41 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: > >> In article <op.0miefkhkwdg98l@glass>, CFKinsey@military.org.jp says... >>> >>> I'd need to contract OCD to understand that. There's only one thing in question here, how close is the reading to the correct value. You can't split that into two. 3.1416 is better than 3.14, and that's it. All you can state with a reading is it's correct to within a certain percentage. >> >> Try this. >> >> A doctor does a very complicated operation on your left arm like a joint >> replacement. It all goes very well. Very precise. >> >> However he should have done the operation on the right arm that was >> causing trouble. Not accurate. > > Nope, because the first one is 100% useless. I wouldn't call that precise at all, as he was out by half a metre. > >> That is why a voltmeter can show 3 digits and be accurate to only the >> last digit being in question by one number either way, but a 5 digit >> volt meter can show many numbers, but if it is not calibrated corrctly >> the 2nd digit to the 5 th digit could be way off and the meter not >> accurate at all. > > Showing those extra two numbers is pointless if they're wrong. All that matters is how many volts difference between the actual voltage and what is shown. agreed. The problem with the bullets and the target story is that when explained, we somehow perfectly know where the bullets are- be in on target or a small grouping somewhere else. Cheapo meters won't give CONSISTENT or REPEATABLE results, not matter how "precise" they pretended to be, or how accurate the spec sheet claims, especially considering the last digit(s) may be totaly wrong, and random. It's like having crappy or dirty test leads or a component. You'll get all the digits in the world, but they keep changing. You won't even be able to pick a reading. Keep in mind that "calibrated" equipment doesn't even have to be precise or accurate. An example would be an adjustable power supply with digital readout. Say it's always reads high by 0.7 volts. It's not precise or accurate, but by knowing the offset it can used with success and may even have great regulation. On the other hand say you have an alibaba special power supply that's "accurate" to +/- 0.35 volts, with terrible regulation that oscillates. What power supply is better? So the point is cheapo equipment can have lots of bogus digits and readings that flop up and down, while better equipment can be more consistently wrong, which can be compensated for. Precision and accuracy mean little by themselves if you need multiple readings.
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| From | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| Date | 2020-07-11 21:38 +0100 |
| Message-ID | <op.0nlya1ikwdg98l@glass> |
| In reply to | #390 |
On Fri, 26 Jun 2020 05:54:19 +0100, Cydrome Leader <presence@mungepanix.com> wrote: > In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote: >> On Sat, 20 Jun 2020 16:24:41 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: >> >>> In article <op.0miefkhkwdg98l@glass>, CFKinsey@military.org.jp says... >>>> >>>> I'd need to contract OCD to understand that. There's only one thing in question here, how close is the reading to the correct value. You can't split that into two. 3.1416 is better than 3.14, and that's it. All you can state with a reading is it's correct to within a certain percentage. >>> >>> Try this. >>> >>> A doctor does a very complicated operation on your left arm like a joint >>> replacement. It all goes very well. Very precise. >>> >>> However he should have done the operation on the right arm that was >>> causing trouble. Not accurate. >> >> Nope, because the first one is 100% useless. I wouldn't call that precise at all, as he was out by half a metre. >> >>> That is why a voltmeter can show 3 digits and be accurate to only the >>> last digit being in question by one number either way, but a 5 digit >>> volt meter can show many numbers, but if it is not calibrated corrctly >>> the 2nd digit to the 5 th digit could be way off and the meter not >>> accurate at all. >> >> Showing those extra two numbers is pointless if they're wrong. All that matters is how many volts difference between the actual voltage and what is shown. > > agreed. The problem with the bullets and the target story is that when > explained, we somehow perfectly know where the bullets are- be in on > target or a small grouping somewhere else. Cheapo meters won't give > CONSISTENT or REPEATABLE results, not matter how "precise" they pretended > to be, or how accurate the spec sheet claims, especially considering the > last digit(s) may be totaly wrong, and random. It's like having crappy or > dirty test leads or a component. You'll get all the digits in the world, > but they keep changing. You won't even be able to pick a reading. > > Keep in mind that "calibrated" equipment doesn't even have to be precise > or accurate. An example would be an adjustable power supply with digital > readout. Say it's always reads high by 0.7 volts. It's not precise or > accurate, but by knowing the offset it can used with success and may even > have great regulation. I've got thermostats like that, I've calibrated them to 0.1C. Trouble is, they have remote sensors which work perfectly, but if the actual unit gets very warm (as in direct sunlight), the reading goes up by as much as 2C. Nevermind, they happen to be in my conservatory (the main source of heat in the summer), along with the air conditioner, so on a hot day they switch it on slightly too soon, then correct themselves when the AC cools them off. > On the other hand say you have an alibaba special power supply that's > "accurate" to +/- 0.35 volts, with terrible regulation that oscillates. > > What power supply is better? > > So the point is cheapo equipment can have lots of bogus digits and > readings that flop up and down, while better equipment can be more > consistently wrong, which can be compensated for. Precision and accuracy > mean little by themselves if you need multiple readings. > >
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-07-13 03:21 +0000 |
| Message-ID | <regk05$34q$1@reader1.panix.com> |
| In reply to | #411 |
In sci.electronics.basics Commander Kinsey <CFKinsey@military.org.jp> wrote: > On Fri, 26 Jun 2020 05:54:19 +0100, Cydrome Leader <presence@mungepanix.com> wrote: > >> In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote: >>> On Sat, 20 Jun 2020 16:24:41 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: >>> >>>> In article <op.0miefkhkwdg98l@glass>, CFKinsey@military.org.jp says... >>>>> >>>>> I'd need to contract OCD to understand that. There's only one thing in question here, how close is the reading to the correct value. You can't split that into two. 3.1416 is better than 3.14, and that's it. All you can state with a reading is it's correct to within a certain percentage. >>>> >>>> Try this. >>>> >>>> A doctor does a very complicated operation on your left arm like a joint >>>> replacement. It all goes very well. Very precise. >>>> >>>> However he should have done the operation on the right arm that was >>>> causing trouble. Not accurate. >>> >>> Nope, because the first one is 100% useless. I wouldn't call that precise at all, as he was out by half a metre. >>> >>>> That is why a voltmeter can show 3 digits and be accurate to only the >>>> last digit being in question by one number either way, but a 5 digit >>>> volt meter can show many numbers, but if it is not calibrated corrctly >>>> the 2nd digit to the 5 th digit could be way off and the meter not >>>> accurate at all. >>> >>> Showing those extra two numbers is pointless if they're wrong. All that matters is how many volts difference between the actual voltage and what is shown. >> >> agreed. The problem with the bullets and the target story is that when >> explained, we somehow perfectly know where the bullets are- be in on >> target or a small grouping somewhere else. Cheapo meters won't give >> CONSISTENT or REPEATABLE results, not matter how "precise" they pretended >> to be, or how accurate the spec sheet claims, especially considering the >> last digit(s) may be totaly wrong, and random. It's like having crappy or >> dirty test leads or a component. You'll get all the digits in the world, >> but they keep changing. You won't even be able to pick a reading. >> >> Keep in mind that "calibrated" equipment doesn't even have to be precise >> or accurate. An example would be an adjustable power supply with digital >> readout. Say it's always reads high by 0.7 volts. It's not precise or >> accurate, but by knowing the offset it can used with success and may even >> have great regulation. > > I've got thermostats like that, I've calibrated them to 0.1C. Trouble > is, they have remote sensors which work perfectly, but if the actual > unit gets very warm (as in direct sunlight), the reading goes up by as > much as 2C. Nevermind, they happen to be in my conservatory (the main > source of heat in the summer), along with the air conditioner, so on a > hot day they switch it on slightly too soon, then correct themselves > when the AC cools them off. Is it the controller that's off by 2C when it warms up?
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| From | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| Date | 2020-07-13 13:32 +0100 |
| Message-ID | <op.0no03qg6wdg98l@glass> |
| In reply to | #415 |
On Mon, 13 Jul 2020 04:21:41 +0100, Cydrome Leader <presence@mungepanix.com> wrote: > In sci.electronics.basics Commander Kinsey <CFKinsey@military.org.jp> wrote: >> On Fri, 26 Jun 2020 05:54:19 +0100, Cydrome Leader <presence@mungepanix.com> wrote: >> >>> In sci.electronics.equipment Commander Kinsey <CFKinsey@military.org.jp> wrote: >>>> On Sat, 20 Jun 2020 16:24:41 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: >>>> >>>>> In article <op.0miefkhkwdg98l@glass>, CFKinsey@military.org.jp says... >>>>>> >>>>>> I'd need to contract OCD to understand that. There's only one thing in question here, how close is the reading to the correct value. You can't split that into two. 3.1416 is better than 3.14, and that's it. All you can state with a reading is it's correct to within a certain percentage. >>>>> >>>>> Try this. >>>>> >>>>> A doctor does a very complicated operation on your left arm like a joint >>>>> replacement. It all goes very well. Very precise. >>>>> >>>>> However he should have done the operation on the right arm that was >>>>> causing trouble. Not accurate. >>>> >>>> Nope, because the first one is 100% useless. I wouldn't call that precise at all, as he was out by half a metre. >>>> >>>>> That is why a voltmeter can show 3 digits and be accurate to only the >>>>> last digit being in question by one number either way, but a 5 digit >>>>> volt meter can show many numbers, but if it is not calibrated corrctly >>>>> the 2nd digit to the 5 th digit could be way off and the meter not >>>>> accurate at all. >>>> >>>> Showing those extra two numbers is pointless if they're wrong. All that matters is how many volts difference between the actual voltage and what is shown. >>> >>> agreed. The problem with the bullets and the target story is that when >>> explained, we somehow perfectly know where the bullets are- be in on >>> target or a small grouping somewhere else. Cheapo meters won't give >>> CONSISTENT or REPEATABLE results, not matter how "precise" they pretended >>> to be, or how accurate the spec sheet claims, especially considering the >>> last digit(s) may be totaly wrong, and random. It's like having crappy or >>> dirty test leads or a component. You'll get all the digits in the world, >>> but they keep changing. You won't even be able to pick a reading. >>> >>> Keep in mind that "calibrated" equipment doesn't even have to be precise >>> or accurate. An example would be an adjustable power supply with digital >>> readout. Say it's always reads high by 0.7 volts. It's not precise or >>> accurate, but by knowing the offset it can used with success and may even >>> have great regulation. >> >> I've got thermostats like that, I've calibrated them to 0.1C. Trouble >> is, they have remote sensors which work perfectly, but if the actual >> unit gets very warm (as in direct sunlight), the reading goes up by as >> much as 2C. Nevermind, they happen to be in my conservatory (the main >> source of heat in the summer), along with the air conditioner, so on a >> hot day they switch it on slightly too soon, then correct themselves >> when the AC cools them off. > > Is it the controller that's off by 2C when it warms up? Yes. The controller is in the conservatory in direct sunlight. The sensor is on a long wire in a cooler room (the living room) which is what I want to control the temperature of. The controller's reading goes up by 2C if it gets really hot, but the AC blows across it, so it doesn't do it wrong for long.
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-06-26 04:23 +0000 |
| Message-ID | <rd3t83$7rs$2@reader1.panix.com> |
| In reply to | #377 |
In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: > On 6/20/2020 4:29 AM, Commander Kinsey wrote: >> On Fri, 19 Jun 2020 23:55:42 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: >> >>> In article <op.0mg7zmz6wdg98l@glass>, CFKinsey@military.org.jp says... >>>> >>>> But what I'm surprised at is a ?5 multimeter (not clamp) not giving a digits error. Maybe precision on a simple voltmeter is cheap as chips nowadays? >>>> >>>> >>> >>> You have to be careful how you throw precision and accurecy around. >>> >>> A meter that shows 4 digits is more precice than one that shows only 3 >>> digits, however the 4 digit one may only be 1% accurate and the 3 digit >>> one may be .5% accurate. >>> >>> It is easy to get precision, but difficule to be accurate. Think of it >>> as shooting a gun. Precision may be how close the bullets land to each >>> other where ever they land on the target, but to be accurate the bullets >>> have to land on the center of the target. Such as all the bullets could >>> land very close to each other, but not even hit the target. >>> >>> As I mentioned, a good meter will not have a digits error outside the +- >>> one digit due to rounding. >> >> That didn't help. I interchange the two. I just want to know how close to the correct reading the readout is. Adding another digit doesn't improve anything if it's incorrect. And shooting all the bullets in one place doesn't help if they all miss. >> > > Take pi as an example. It can be said that 3.14 is accurate as a > three-digit value, but 3.1416 is more precise because it has a > higher resolution. > > OTOH, deriving it from 22/7 or 3.1429 has the same 5-digit > resolution and is just as precise as far as the number it > represents is concerned but is less accurate. > > In this particular case, 3.1416 is both more precise and more > accurate than 3.14 but that's not always the case with measurements. > > My mechanical slide caliper has a resolution of 0.001 inch. This > means that it can display measurements with a precision of 1 mil, What if your caliper had a resolution of 1 mil +/- 3 counts on the last digit? That's the issue with multimeters that have completely bogus digits at the end. Those number are just noise and serve no purpose at all. They don't even compare to all bullets missing the target but landing in the same wrong spot. > but that doesn't guarantee that a measurement taken with it will > be accurate to 1 mil. I may not always press the jaws snugly > enough and the scale may not be perfectly accurate.
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| From | Pimpom <nobody@nowhere.com> |
|---|---|
| Date | 2020-06-26 14:02 +0530 |
| Message-ID | <toiJG.81089$Fm.43191@fx28.ams1> |
| In reply to | #389 |
On 6/26/2020 9:53 AM, Cydrome Leader wrote: > In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >> >> My mechanical slide caliper has a resolution of 0.001 inch. This >> means that it can display measurements with a precision of 1 mil, > > What if your caliper had a resolution of 1 mil +/- 3 counts on the last > digit? That's the issue with multimeters that have completely bogus digits > at the end. Those number are just noise and serve no purpose at all. They > don't even compare to all bullets missing the target but landing in the > same wrong spot. > You seem intent on picking an argument by inserting a statement that agrees with the following sentences. BTW, my caliper is not digital, so the matter of +/- count is irrelevant. >> but that doesn't guarantee that a measurement taken with it will >> be accurate to 1 mil. I may not always press the jaws snugly >> enough and the scale may not be perfectly accurate. >
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| From | Cydrome Leader <presence@MUNGEpanix.com> |
|---|---|
| Date | 2020-06-27 06:56 +0000 |
| Message-ID | <rd6qi8$na1$1@reader1.panix.com> |
| In reply to | #392 |
In sci.electronics.basics Pimpom <nobody@nowhere.com> wrote: > On 6/26/2020 9:53 AM, Cydrome Leader wrote: >> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >>> >>> My mechanical slide caliper has a resolution of 0.001 inch. This >>> means that it can display measurements with a precision of 1 mil, >> >> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >> digit? That's the issue with multimeters that have completely bogus digits >> at the end. Those number are just noise and serve no purpose at all. They >> don't even compare to all bullets missing the target but landing in the >> same wrong spot. >> > You seem intent on picking an argument by inserting a statement > that agrees with the following sentences. BTW, my caliper is not > digital, so the matter of +/- count is irrelevant. electronic test equipment is digital these days, so my question is very valid. How would you feel if your vernier or thimble readouts on your hand tools had number that randomly moved around? That's the goofiness of how these digital integrating meters work. It makes very little sense when directly translated into the physical word. Take a 100 foot surveyor's tape measure. Those are simple to read. You have feet and inches, and they're all in order. Let's our 100 foot tape is accurate to 3inches over that 100 feet. Not great, but fine for us. Now go digital, with the analog feel. Say the tape is now a long e-ink display and has no factory printed numers on it like a conventional tape. Every time you pull the tape out it redisplays tape measure printing and you get stuff like this: ... 12ft 1in 2in 4in 5in 3in 6in 7in 8in 9in 11in 10in 13ft ... How would that feel? It makes absolutely no sense unless you understand the silly types of errors that are display on devices where we expect direct read out of numbers. >>> but that doesn't guarantee that a measurement taken with it will >>> be accurate to 1 mil. I may not always press the jaws snugly >>> enough and the scale may not be perfectly accurate. crappy meters can lack "snug" readings.
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| From | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| Date | 2020-07-12 18:45 +0100 |
| Message-ID | <op.0nnkyvd1wdg98l@glass> |
| In reply to | #389 |
On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> wrote: > In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >> On 6/20/2020 4:29 AM, Commander Kinsey wrote: >>> On Fri, 19 Jun 2020 23:55:42 +0100, Ralph Mowery <rmowery28146@earthlink.net> wrote: >>> >>>> In article <op.0mg7zmz6wdg98l@glass>, CFKinsey@military.org.jp says... >>>>> >>>>> But what I'm surprised at is a ?5 multimeter (not clamp) not giving a digits error. Maybe precision on a simple voltmeter is cheap as chips nowadays? >>>>> >>>>> >>>> >>>> You have to be careful how you throw precision and accurecy around. >>>> >>>> A meter that shows 4 digits is more precice than one that shows only 3 >>>> digits, however the 4 digit one may only be 1% accurate and the 3 digit >>>> one may be .5% accurate. >>>> >>>> It is easy to get precision, but difficule to be accurate. Think of it >>>> as shooting a gun. Precision may be how close the bullets land to each >>>> other where ever they land on the target, but to be accurate the bullets >>>> have to land on the center of the target. Such as all the bullets could >>>> land very close to each other, but not even hit the target. >>>> >>>> As I mentioned, a good meter will not have a digits error outside the +- >>>> one digit due to rounding. >>> >>> That didn't help. I interchange the two. I just want to know how close to the correct reading the readout is. Adding another digit doesn't improve anything if it's incorrect. And shooting all the bullets in one place doesn't help if they all miss. >>> >> >> Take pi as an example. It can be said that 3.14 is accurate as a >> three-digit value, but 3.1416 is more precise because it has a >> higher resolution. >> >> OTOH, deriving it from 22/7 or 3.1429 has the same 5-digit >> resolution and is just as precise as far as the number it >> represents is concerned but is less accurate. >> >> In this particular case, 3.1416 is both more precise and more >> accurate than 3.14 but that's not always the case with measurements. >> >> My mechanical slide caliper has a resolution of 0.001 inch. This >> means that it can display measurements with a precision of 1 mil, > > What if your caliper had a resolution of 1 mil +/- 3 counts on the last > digit? That's the issue with multimeters that have completely bogus digits > at the end. Those number are just noise and serve no purpose at all. They > don't even compare to all bullets missing the target but landing in the > same wrong spot. In America, what is a "mill"? In the UK, it used to mean a thousandth of an inch, but people use it to mean a millimetre nowadays. >> but that doesn't guarantee that a measurement taken with it will >> be accurate to 1 mil. I may not always press the jaws snugly >> enough and the scale may not be perfectly accurate. >
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| From | Pimpom <nobody@nowhere.com> |
|---|---|
| Date | 2020-07-12 23:31 +0530 |
| Message-ID | <ydIOG.97454$FL7.15901@fx12.ams1> |
| In reply to | #412 |
On 7/12/2020 11:15 PM, Commander Kinsey wrote: > On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> wrote: > >> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >>> My mechanical slide caliper has a resolution of 0.001 inch. This >>> means that it can display measurements with a precision of 1 mil, >> >> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >> digit? .....<snip>........ > > In America, what is a "mill"? In the UK, it used to mean a thousandth of an inch, but people use it to mean a millimetre nowadays. > It's not a mill. It's mil - single l. It means, and has always meant, a thousandth of an inch. It's not an Americanism.
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| From | Tom Gardner <spamjunk@blueyonder.co.uk> |
|---|---|
| Date | 2020-07-12 20:21 +0100 |
| Message-ID | <HoJOG.897349$imF1.670723@fx15.am4> |
| In reply to | #413 |
On 12/07/20 19:01, Pimpom wrote: > On 7/12/2020 11:15 PM, Commander Kinsey wrote: >> On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> >> wrote: >> >>> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: > >>>> My mechanical slide caliper has a resolution of 0.001 inch. This >>>> means that it can display measurements with a precision of 1 mil, >>> >>> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >>> digit? > .....<snip>........ >> >> In America, what is a "mill"? In the UK, it used to mean a thousandth of an >> inch, but people use it to mean a millimetre nowadays. >> > > It's not a mill. It's mil - single l. It means, and has always meant, a > thousandth of an inch. It's not an Americanism. In the UK "mill" means millilitre. If you want to refer to fractions of an inch, then it is /always/ "thou", i.e. thousandths of an inch. In the UK "mil/mill" /never/ means 0.001".
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| From | Pimpom <nobody@nowhere.com> |
|---|---|
| Date | 2020-07-13 10:23 +0530 |
| Message-ID | <fNROG.48466$8b2.9841@fx07.ams1> |
| In reply to | #414 |
On 7/13/2020 12:51 AM, Tom Gardner wrote: > On 12/07/20 19:01, Pimpom wrote: >> On 7/12/2020 11:15 PM, Commander Kinsey wrote: >>> On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> >>> wrote: >>> >>>> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >> >>>>> My mechanical slide caliper has a resolution of 0.001 inch. This >>>>> means that it can display measurements with a precision of 1 mil, >>>> >>>> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >>>> digit? >> .....<snip>........ >>> >>> In America, what is a "mill"? In the UK, it used to mean a thousandth of an >>> inch, but people use it to mean a millimetre nowadays. >>> >> >> It's not a mill. It's mil - single l. It means, and has always meant, a >> thousandth of an inch. It's not an Americanism. > > In the UK "mill" means millilitre. > > If you want to refer to fractions of an inch, then > it is /always/ "thou", i.e. thousandths of an inch. > > In the UK "mil/mill" /never/ means 0.001". > My bad. This is the first time I heard that the mil is not used as the unit for .001" in the UK. (I'm *not* an American).
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| From | "Commander Kinsey" <CFKinsey@military.org.jp> |
|---|---|
| Date | 2020-07-13 13:36 +0100 |
| Message-ID | <op.0no1akk5wdg98l@glass> |
| In reply to | #416 |
On Mon, 13 Jul 2020 05:53:29 +0100, Pimpom <nobody@nowhere.com> wrote: > On 7/13/2020 12:51 AM, Tom Gardner wrote: >> On 12/07/20 19:01, Pimpom wrote: >>> On 7/12/2020 11:15 PM, Commander Kinsey wrote: >>>> On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> >>>> wrote: >>>> >>>>> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >>> >>>>>> My mechanical slide caliper has a resolution of 0.001 inch. This >>>>>> means that it can display measurements with a precision of 1 mil, >>>>> >>>>> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >>>>> digit? >>> .....<snip>........ >>>> >>>> In America, what is a "mill"? In the UK, it used to mean a thousandth of an >>>> inch, but people use it to mean a millimetre nowadays. >>>> >>> >>> It's not a mill. It's mil - single l. It means, and has always meant, a >>> thousandth of an inch. It's not an Americanism. >> >> In the UK "mill" means millilitre. >> >> If you want to refer to fractions of an inch, then >> it is /always/ "thou", i.e. thousandths of an inch. >> >> In the UK "mil/mill" /never/ means 0.001". >> > > My bad. This is the first time I heard that the mil is not used > as the unit for .001" in the UK. (I'm *not* an American). If you're not American why did you say "my bad"? Your bad what? Finish the sentence!
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| From | Pimpom <nobody@nowhere.com> |
|---|---|
| Date | 2020-07-13 20:57 +0530 |
| Message-ID | <y3%OG.142619$t27.56386@fx34.ams1> |
| In reply to | #419 |
On 7/13/2020 6:06 PM, Commander Kinsey wrote: > On Mon, 13 Jul 2020 05:53:29 +0100, Pimpom <nobody@nowhere.com> wrote: > >> On 7/13/2020 12:51 AM, Tom Gardner wrote: >>> On 12/07/20 19:01, Pimpom wrote: >>>> On 7/12/2020 11:15 PM, Commander Kinsey wrote: >>>>> On Fri, 26 Jun 2020 05:23:31 +0100, Cydrome Leader <presence@mungepanix.com> >>>>> wrote: >>>>> >>>>>> In sci.electronics.equipment Pimpom <nobody@nowhere.com> wrote: >>>> >>>>>>> My mechanical slide caliper has a resolution of 0.001 inch. This >>>>>>> means that it can display measurements with a precision of 1 mil, >>>>>> >>>>>> What if your caliper had a resolution of 1 mil +/- 3 counts on the last >>>>>> digit? >>>> .....<snip>........ >>>>> >>>>> In America, what is a "mill"? In the UK, it used to mean a thousandth of an >>>>> inch, but people use it to mean a millimetre nowadays. >>>>> >>>> >>>> It's not a mill. It's mil - single l. It means, and has always meant, a >>>> thousandth of an inch. It's not an Americanism. >>> >>> In the UK "mill" means millilitre. >>> >>> If you want to refer to fractions of an inch, then >>> it is /always/ "thou", i.e. thousandths of an inch. >>> >>> In the UK "mil/mill" /never/ means 0.001". >>> >> >> My bad. This is the first time I heard that the mil is not used >> as the unit for .001" in the UK. (I'm *not* an American). > > If you're not American why did you say "my bad"? Your bad what? Finish the sentence! > So now you're a grammar Nazi? This after I (and others) spent considerable time and effort patiently explaining to you a concept that many/most readers here probably already knew, and would quickly grasp if they didn't. Sheesh! And is there a law against non-Americans using an American expression? FYI I'm none of these: American, British, Australian or Canadian - or a citizen of any other country where English is natively spoken.
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| From | Jeroen Belleman <jeroen@nospam.please> |
|---|---|
| Date | 2020-07-13 17:39 +0200 |
| Message-ID | <rehv7v$e6s$1@gioia.aioe.org> |
| In reply to | #421 |
On 2020-07-13 17:27, Pimpom wrote: > On 7/13/2020 6:06 PM, Commander Kinsey wrote: [...] >> If you're not American why did you say "my bad"? Your bad what? >> Finish the sentence! >> > So now you're a grammar Nazi? This after I (and others) spent > considerable time and effort[...] Just drop it. There are better things to do than to argue with a cantankerous teenager. If a conversation turns into a source of irritation, the best way is to simply drop out. Jeroen Belleman
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