Does anyone know if there is a military procedure for testing the Fluke A40/A40A current shunts? I didn't see it on gidep and fluke doesn't have a procedure or specs on there website anymore.
Thanks
Hi, this is a resistor isn't it ?
googled fluke a40. . . . . .
http://us.fluke.com/usen/products/specifications.htm?cs_id=7845(FlukeProducts)&category=ALLCAL(FlukeProducts)
edit: fixed link
hoopty
I was in the process of typing a similar answer. They are still out there. According to the Fluke web page, "...contact your Fluke rep for details." This is one of those oddballs they apparently just don't put on the website. I would send an email or call Fluke to get specs.
The one thing it does say is: "BEST 1 YEAR AC-DC SPECIFICATION: +/-0.02% 5 HZ to 100 KHZ."
Quote from: Hawaii596 on 02-17-2009 -- 10:41:09
I was in the process of typing a similar answer. They are still out there. According to the Fluke web page, "...contact your Fluke rep for details." This is one of those oddballs they apparently just don't put on the website. I would send an email or call Fluke to get specs.
The one thing it does say is: "BEST 1 YEAR AC-DC SPECIFICATION: +/-0.02% 5 HZ to 100 KHZ."
Yeah, I saw this. I just wasn't sure if that was for all the shunts across the entire frequency range. Or just the best shunt or frequency. I will contact them and see what they say.
Im not sure there is a military cal procedure produce for the A40A set yet. the largest contract thus far has been for the USAF and I believe they are still fine tuning the procedure.
Fluke now has the A40B shunt set out, and there is a calibration procedure for those in the manual, and I don't see why the same process couldn't apply to the A40 set. It calls for a Clarke-Hess 8100 transconductance amp driven by a Fluke 5720A, and the UUT shunt is wired in series with a primary shunt whose value is determined by NIST. (How they determine their value is anybody's guess.) They are both compared with thermal voltage converters (such as a Fluke 792A).
For my applications, I simply determine the resistance of the shunt by applying first a positive DC current then a negative DC current at the AC current I'm looking to compare, and measuring the output voltage with either an 8508A or 5790A. I enter the values into a spreadsheet to calculate the values in the positive current direction then the negative direction, then average the two to cancel out thermal emfs. I then use the calculated resistance to determine the AC current. Of course this method requires the DC current source to be calibrated.
Snap,
There is a cal T.O. for the A40/A40A, The problem is this unit is has an AFPSL Cal Authority so we ship our's to AFPSL, The AFPSL Cal procedure is 33k8-5-4-1 so I am pretty sure it would not be on GIDEP.
These are the specs I have listed for the shunt. Sorry but it's all we have here.
Specification Group: 10 mA to 5 A
• Range: [Shunt Value] 0.01 A to 5 A
• Range: [Frequency] 0.005 kHz to 20 kHz
• Accuracy: +/-(0.02% I.V.)
Specification Group: 10 mA to 5 A
• Range: [Shunt Value] 0.01 A to 5 A
• Range: [Frequency] 20 kHz to 50 kHz
• Accuracy: +/-(0.03% I.V.)
Specification Group: 10 A to 20 A
• Range: [Shunt Value] 10 A to 20 A
• Range: [Frequency] 0.005 kHz to 20 kHz
• Accuracy: +/-(0.03% I.V.)
Specification Group: 10 A to 20 A
• Range: [Shunt Value] 10 A to 20 A
• Range: [Frequency] 20 kHz to 50 kHz
• Accuracy: +/-(0.05% I.V.)
Specification Group: 10 mA to 5 A
• Range: [Shunt Value] 0.01 A to 5 A
• Range: [Frequency] 50 kHz to 100 kHz
• Accuracy: +/-(0.05% I.V.)
33K1-4-947-1 is the generic T.O. for current shunts just in case that would help any.
The terminals have an odd spacing that doesn't line up with any meters I have, anybody know of a proper adapter?
http://us.fluke.com/usen/Products/A40+A40A.htm?catalog_name=FlukeUnitedStates&category=PMELESTD(FlukeProducts)
i think this link works
There's a very good chance of a new product being released early 2010 with improved specifications, features & benefits that will be extremely useful in calibrating 5500, 5520, 5700, 5720, 3458, 8508's. Ranges will include 1, 2, 5, 10 20, 50 & 100 amps to 20kHz and beyond...best of all it will be reasonably priced!
REJUVENATING THE A40 topic.....
Getting ready to get my 792A and A40's activated. I have a 100mA, 1A and 2A. What others do I need to reasonably have for cals of 5720A, 3458A and/or 8508A? Also, in reference to earlier answers, in my ignorant opinion, I don't think I should or could cal these myself, should I? If I have a 792A that I will have cal'd by Fluke Primary lab or equivalent, I still need to send these out for primary lab cal also, wouldn't I? Or should I be able to somehow do them using the AC-DC accuracy of the 792A (I'm thinking not)?
To begin with, the A40/A40A units are quite different than the newer A40Bs. The former are specified (and calibrated) for AC-DC difference only (transfer standards), while the A40Bs are specified and calibrated for absolute (DC) resistance as well as AC-DC difference. Practically speaking, this means that to calibrate AC current using the A40/A40A, one must have an known DC current source from which to 'transfer' from, while the A40Bs, using their reported value(s) in conjunction with the AC-DC difference, can be used as absolute standards, without the requirement of a DC current source. However, even when using the A40Bs, the measurement uncertainty can be reduced if a DC current source, known more precisely than simply measuring it using the A40B, i.e., establishing its value using a lower uncertainty shunt and subsequently using it for transfer in conjunction with the A40B reported AC-DC difference.
As far as calibrating A40/A40A units, that too is somewhat different than the A40B in that A40Bs require the measurement of their DC resistance during calibration, in addition to determining their AC-DC difference, while the A40/A40A require only the latter. The AC-DC difference determination is typically made while comparing the unit under test vs. a AC-DC current shunt calibrated by a high echelon lab, e.g., NIST. It should be noted that both A40/A40A and A40B units must be calibrated with the 792A and/or the 5790A they are intended to be used with, especially in the case of the 5790A, due to common mode effects. I'm sure Fluke would readily explain this, if asked.
Hope this helps!
Thanks for that informative input. Getting ready to work on this, and every bit helps.
Not sure how well I posted previously but, can one of the A40 experts tell me which values of A40 do you minimally need to have to calibrate a Fluke 5720A AC current? I have the few shunts and working on bringing the lab online over the next year. So I've been asked by management to provide them with a list of what smallerr items in the lab I need to fully do the calibrations to the Fluke 5720A. On a related note, I've seen that there is a Holt shunt set that can alternately be used for the high accuracy AC current cals. Any thoughts on that? If I only have 100mA, 1A and 2A A40's, are there enough more shunts needed that a good used (and re-certified) Holt set might be a more cost effective, yet accurate enough solution?
Quote from: Hawaii596 on 02-08-2013 -- 08:15:29
Not sure how well I posted previously but, can one of the A40 experts tell me which values of A40 do you minimally need to have to calibrate a Fluke 5720A AC current? I have the few shunts and working on bringing the lab online over the next year. So I've been asked by management to provide them with a list of what smallerr items in the lab I need to fully do the calibrations to the Fluke 5720A. On a related note, I've seen that there is a Holt shunt set that can alternately be used for the high accuracy AC current cals. Any thoughts on that? If I only have 100mA, 1A and 2A A40's, are there enough more shunts needed that a good used (and re-certified) Holt set might be a more cost effective, yet accurate enough solution?
In the AF CTO for the 5720A (When they used the A40A Current Shunts) they used the 2 A, 500 mA and 20 mA shunts, of course if you have a 5725A with your 5720A you would require the 20 A shunt. The 2.2 mA range of the 5720A is calibrated using a 200 Ohm Metal Film Resistor and the 220 uA range uses a 2 kOhm resistor. The Holt set is listed as a sub-item, not sure about the accuracies though. The AF cals the 5720A current ranges at a value of 2 for the 2.2 ranges.
Fluke says you need 20mA/200mA/2A and 10A if a 5725A is included. The 2mA and 200uA ranges are tested using 200 and 2 K ohm precision resistors. I use a 20A on my 5725 and 500mA instead of the 200mA. What I do not know is the dynamic range of the things, they were offered in 1, 2, 5 values. So how do they perform at half scale or 10% of scale, I cannot answer that with anything concrete but I have had good results with 20mA/500mA/2A and 20A. Maybe some can chime in with more authorita. I think we had a complete set at one time but in a cost containing measure several years ago I cut us back to 20mA, 500mA (would have preferred 200mA but it was smoked), 2A and 20A figuring that would give the best acceptable coverage presuming they can run from about 25 to 100% and perform well.
The 200 ohm & 2 kohm are not precision resistors, they are metal film resistors ±1% of value AC/DC difference negligible due to metal film construction.
Quote from: beadwork on 02-11-2013 -- 06:31:07
The 200 ohm & 2 kohm are not precision resistors, they are metal film resistors ±1% of value AC/DC difference negligible due to metal film construction.
Thanks beadwork
Quote from: Bryan on 02-08-2013 -- 12:00:28
Fluke says you need 20mA/200mA/2A and 10A if a 5725A is included. The 2mA and 200uA ranges are tested using 200 and 2 K ohm precision resistors. I use a 20A on my 5725 and 500mA instead of the 200mA. What I do not know is the dynamic range of the things, they were offered in 1, 2, 5 values. So how do they perform at half scale or 10% of scale, I cannot answer that with anything concrete but I have had good results with 20mA/500mA/2A and 20A. Maybe some can chime in with more authorita. I think we had a complete set at one time but in a cost containing measure several years ago I cut us back to 20mA, 500mA (would have preferred 200mA but it was smoked), 2A and 20A figuring that would give the best acceptable coverage presuming they can run from about 25 to 100% and perform well.
Actually, Bryan, A40s were offered in 1, 2, 3, 5 increments, beginning with 10 mA, A40 model and ending with the A40A 20 A unit. Initially, the aforementioned values were required, due to the limited dynamic range of the thermocouple-based Fluke 540B, which was used as the detector. Now, even though better dynamic range is achievable using a Fluke 792A or 5790A, problems with low-level and/or common-mode noise can still be a problem. Best advice: When using the A40(A) series of AC-DC Current Shunts, utilize the value closest to that you are trying to measure. Also remember that the shunts themselves will only tolerate perhaps a 10% overload prior to undesirable things occurring.