Specifications - Fluke 87 TRUE RMS MULTIMETER User Manual

87
Users Manual
Function Range
400.0 mV
V † 4.000V
40.00V
400.0V
1000v
* Accuracy is given as ([% of reading] + [number] + [number of lease significant digits]) at 18°C to 28°C, with relative
humidity up to 90%, for a period of one year after calibration. In the 4 ½-digit mode, multiply the number of lease
significant digits (counts) by 10. AC conversions are ac-coupled, true rms responding, calibrated to the rms value of
a sine wave input, and valid from 5% to 100% of range. AC crest factor can be up to 3 at full scale, 6 at half scale.
For non-sinusoidal wave forms add -(2% Rdg +2% Fs) typical, for a crest factor up to 3.
** Below 10% of range, add 16 counts.
*** Below 10% of range, add 6 digits.
† The Fluke 87 is a True-RMS responding meter. The meter will display a reading (typically <25 digits) when the input
leads are shorted together in the AC functions which is caused by internal amplifier noise. The accuracy on the
Fluke 87 is not significantly affected by this internal offset when measuring inputs that are within 5% to 100% of the
selected range. When the RMS value of the two values (5% of range and internal offset) is calculated, the effect is
minimal as shown in the following example where 20.0 = 5% of 400 mV range, and 2.5 is the internal offset.
RMS = SQRT[(20.0)
If you use the REL function to zero the display when using the AC functions, a constant error that is equal to the
internal offset will result.
‡ Frequency range: 1 kHz to 2.5 kHz.
36
Resolution
50 Hz - 60 Hz
0.1 mV (0.7% + 4)
0.001V (0.7% + 2)
0.01V (0.7% + 2)
0.1V (0.7% + 2)
1V (0.7% + 2)
2 2
+ (2.5) ] = 20.16

Specifications

45 Hz - 1 kHz
(1.0% + 4)
(1.0% + 4)
(1.0% + 4)
(1.0% + 4)
(1.0% + 4)**
Accuracy*
1 kHz - 5 kHz 5 kHz - 20 kHz***
(2.0% + 4)
(2.0% + 4)
(2.0% + 4)
(2.0% + 4)‡
unspecified
(2.0% + 20)
(2.0% + 20)
(2.0% + 20)
unspecified
unspecified