How to understand the accuracy parameter (1.5% + 3) of the Fluke F17B+ multimeter?

bobde163

How to understand the accuracy parameter (1.5% + 3) of the Fluke F17B+ multimeter? [Copy link]

Today I need to use Fluke F17B+ multimeter to measure uA current, which is different from the measurement of another Uni-T UT890C+. Therefore, I think about the measurement accuracy. I found the description of accuracy in the specifications of these two meters, but I don’t understand the representation method. The F17B+ is as follows:

Accuracy specifications take the form of: ±([% of Reading] + [Number of Least Significant Digits]) .

The instructions in Uni-T's UT890C+ are as follows:

They are all similar to the expression method of (1.5% + 3). My understanding is that the true value = the value displayed on the table x 1.5% + 3. For example, the table shows 1uA, and the actual calculation is 1.015+3=4.015uA. In this case, wouldn’t the error be very large? I would like to ask forum friends who understand to give me some advice.

chineseboyzxy

That 3 should be added to the last digit on the display.

bobde163

chineseboyzxy posted on 2020-11-20 14:19 That 3 should be added to the last digit of the display.

I searched carefully on Baidu again, and it is similar to what you said. The 17B+ uA file has 1 decimal place, so adding 3 to the decimal place makes sense. The same is true for UT890C+

笑揖春风

Poor Hamartoma, it's so terrible

guojun0718

Accuracy generally refers to full scale.