so ive been looking at ebay for a used fluke 87 and found some III's and V's
i had posted a previous question about buying safely on ebay for a fluke and i got the hang of it but now i wanted to ask about what to do when i actually go the thing.
i do have access to a physics lab with power supplies and such so i can test the meter out that way but if its messed up how much would it cost to calibrate the meter (if its either the III or V) and get back to working order? would it be wise to go ahead and get it calibrated or whatever anyways when i get it?
there are some meters that do not come with leads and cases. how much would it usually cost to get them?
do flukes hold up for a good period of time when being used? as in their readings are good and such if it looks and sounds like it wasnt terrible abused or used?
What is the differnce between the fluke 87 III and the fluke 87 V? i wanted to make sure bc all i can remember is that hte V is just newer and thats it.
if you have any other advice/suggestions i would appreciate. thanks
BTW, a quick test to help ensure your Fluke is still accurate and working is to probe the uA/mA socket while on ohms. It should read pretty close to spot on 1K
Useful if doing a quick inspection before buying 2nd hand or whatever, or asking an ebay seller to do who "doesn't know how to test these things"
Dave.
Is this going to ensure the accuracy and functionality of all the functions or simply the resistance measurement?
BTW, a quick test to help ensure your Fluke is still accurate and working is to probe the uA/mA socket while on ohms. It should read pretty close to spot on 1K
Useful if doing a quick inspection before buying 2nd hand or whatever, or asking an ebay seller to do who "doesn't know how to test these things"
Dave.
One Tip for all, touch the lead at the inner upper area at the leads hole ..
Just at the very begging of the hole ..
Or else you will get LEAD alarm and 1.5 MOhm readings ..
plugging the black lead in the red jack, and you can explain that the current doesn't care.)
"Back in my day, we didn't have "lead warnings," and we LIKED it."
Back in my day, we was riding dinosaurs , bad we do not do that any more ,Plus the fuel probably got too expensive ;).
it damages the highway .. ;D
No, but it tells you that the reference voltage is spot on, and probably part of the precision resistor network as well. As it's unlikely that the current shunt resistor would drift in the opposite direction to the voltage reference reference and give you a "false positive" reading for example.Nice way to test basic voltage measurement, the current source for resistance measurements, and the internal low-current shunt. The main things it misses are parts of the divider network, both for resistance and for voltage, and the 10A shunt. I do occasionally see meters with defects like dead high resistance ranges or a dead voltage range, but you have to cycle through the all ranges with something like a battery and a resistor to test those. Another possible issue is the calibration constants (eg. some idiot messed with the calibration), these are fixable, but might almost double the price if you got the meter for something like $100. These are often separate for each range and function, so you have to test all ranges for those.
I'd be very surprised if you could have resistance measure spot on and voltage be out of spec for example (in a fluke, other meters may vary).
Dave, would you allow me to add this check to my Ebay Fluke guides?
If you plug any lead at the " uA Amp " ranges at the Ohm scale , you get LEAD alarm on the spot.
Touching the Positive lead ( Ohm ) at the " uA Amp " ranges as I described above,
are the only way to do this test.
If you plug any lead at the " uA Amp " bananas and the meter are at the Ohm mode , you get LEAD alarm on the spot.Do we agree here ... ?
Touching the Positive lead ( Ohm ) at the " uA or Amperes " bananas as I described above,
are the only way to do this test.
Mine shows 0.9985K, not quite spot-on.Its best to check your battery first , and then to do the test.
Ok my last attempt to express my self .. correctly :DQuoteIf you plug any lead at the " uA Amp " bananas and the meter are at the Ohm mode , you get LEAD alarm on the spot.Do we agree here ... ?
Touching the Positive lead ( Ohm ) at the " uA or Amperes " bananas as I described above,
are the only way to do this test.
If you plug any lead at the " uA Amp " ranges at the Ohm scale , you get LEAD alarm on the spot.
Touching the Positive lead ( Ohm ) at the " uA Amp " ranges as I described above,
are the only way to do this test.
No, you can do it as Excavatoree said. Yes, the meter beeps at you and shows "LEAD", but it also alternates the display between the actual reading.
Mine shows 0.9985K, not quite spot-on.
Dave.
BTW , if the resistance of the percsision resistor changes via the tem'p , canno't we compenset that via thermistor/thermo couple ? (IE , define that every 0.1C = 0.02ppm to add or something like this ..)This trick is used by TCXOs (temperature compensated crystal oscillators). Sometimes components with an opposite tempco are used in series to decrease the net tempco. The trouble with sensing the shunt resistor temperature is that you need to measure the resistor temperature accurately. Since the resistor is dissipating power, its core will always be hotter than its case. You could model this with the thermal resistance, but it's probably more trouble than it's worth, a more expensive resistor with a lower tempco is probably cheaper. Putting the shunt resistor in an oil bath appears to be more common, but is not very practical in a handheld meter.
But i cant seem to find the date of manufacture for the 87-series 3 .User manual has a copyright date of Oct 1997 suggesting the first III series was likely introduced sometime in 1997.
Yeah i read that 87 -3 switched background light in the meantime . First 87-3 models had green ,battery destroying back light.
Yeah i read that 87 -3 switched background light in the meantime . First 87-3 models had green ,battery destroying back light.
Wait, what? Can anyone elaborate on this? Why is it battery destroying?
Earlier/inital versions of the 87 III used a green colored backlight. Later versions switched to a white backlight which reduced battery consumption.Yeah i read that 87 -3 switched background light in the meantime . First 87-3 models had green ,battery destroying back light.
Wait, what? Can anyone elaborate on this? Why is it battery destroying?
I just checked the 87-III service manual, and it only mentions "Backlight, White" in the parts list ...
FYI, my 87-V (manufactured in 2014) reads 1.0015.
Earlier/inital versions of the 87 III used a green colored backlight. Later versions switched to a white backlight which reduced battery consumption.Yeah i read that 87 -3 switched background light in the meantime . First 87-3 models had green ,battery destroying back light.
Wait, what? Can anyone elaborate on this? Why is it battery destroying?
I just checked the 87-III service manual, and it only mentions "Backlight, White" in the parts list ...
FYI, my 87-V (manufactured in 2014) reads 1.0015.
OK, but why?Ebay seller a-fluke, had a listing, that described the difference between the two and why? I don't see a listing from him at this moment.
OK, but why?Ebay seller a-fluke, had a listing, that described the difference between the two and why? I don't see a listing from him at this moment.
I can't test because I don't have a 87 III.
Thanks man, very interesting. Are you a-fluke on eBay?
Fluke 88 (green BL) | Fluke 87 III (white BL) | Fluke 87 V (white BL) | |
off | 9.6µA | 8.6µA | 0.1µA |
VDC | 760µA | 920µA | 1.15mA |
VDC, BL on | 22mA | 26mA | 9.18mA (Level 1), 21.2mA (Level 2) |
Thanks man, very interesting. Are you a-fluke on eBay?
Obviously it's 2x2 green LEDs in series at 30 mA each. You could probably replace those 130 ohm resistors with 1k ones and it would still be bright enough. Do you know if the models with the green backlight have a backlight timer?
One downside I found is that the 87-III doesn't sound the beeper in diode test mode. Bummer.
The different bargraph types of the 87-III vs the 87-V are also curious ...