Products > Test Equipment

when do you really need 6 1/2 DMM ? , I mean the res and/or the accuracy

(1/9) > >>

eevblogfan:
hey

nince I've got 2X HP3478A and 1X HP34401 , I thought , when do you guys really use that kind of res ?  or that kind of accuracy  ?

I had to work with 2uV Chopper amp , so low voltage and good accuracy is an issue , hence 5.5Digit is needed indeed  ' but apart from that , what els ?

please feel free to shear any experiance or experiment you've had with that such need , good night guys  :=\

Fsck:
should let you guarantee that the first 3.5-4.5 digits are 100% accurate.

c4757p:

--- Quote from: Fsck on May 16, 2013, 10:32:34 pm ---should let you guarantee that the first 3.5-4.5 digits are 100% accurate.

--- End quote ---

That's not how it works. For example, the 3478A specifies 0.035% + 40c on the 30mV range, which means if you are measuring 20mV, the meter can read up to 20.011 mV. 300mV range (more similar to the rest of the ranges) measuring 200mV can read up to 200.019 mV, which is only 3.5 "100% accurate" digits. (You did say "3.5-4.5", but you're pretty unlikely to get 4.5 perfect without a really good meter.)

And to contrast, the Fluke 8050A (only a 4.5 digit meter) still gives you 3.5 "perfectly accurate" digits, with a 1-year accuracy on all ranges of 0.03% + 2c.

Fsck:

--- Quote from: c4757p on May 16, 2013, 10:33:10 pm ---
--- Quote from: Fsck on May 16, 2013, 10:32:34 pm ---should let you guarantee that the first 3.5-4.5 digits are 100% accurate.

--- End quote ---

That's not how it works.

--- End quote ---
maybe not 100%, since the confidence interval is probably 95%, but even if you jump to 7-8 sigma interval, and assuming the calibration is correct, the first couple digits will be guaranteed

vk6zgo:
It's so you can show it off to the other Geeks! ;D

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version