Frequency Counter Sensitivity; Min Max, Recording, And Peak Specifications; Input Characteristics - Fluke 287C Calibration Manual

Frequency Counter Sensitivity

Approximate Voltage Sensitivity
(rms sine wave)
Input Range
50 mV
500 mV
5 V
50 V
500 V
1000 V
Approximate Current Sensitivity
Input Range
500 μA
5000 μA
50 mA
400 mA
5 A
10 A
[1] Maximum input = 10 x range (1000 V maximum, 2 x 10
amplitudes may affect accuracy.
[2] Typical frequency bandwidth with full scale (or maximum 2 x 10
For 10 μs < pulse width <25 μs add 1%. For 2 μs < pulse width ≤10 Ω add 3.5 %.
[3]

MIN MAX, Recording, and Peak Specifications

Function
200 ms to 80% (dc function)
MIN MAX, Recording
350 ms to 80 % (ac function)
Peak 250 μS (peak)
Crest Factor 350 ms to 80 %
[1] For repetitive peaks; 2.5 ms for single events. Peak not specified for 500 µA DC, 50 mA DC, 5 A DC.
[2] 200 counts in 500 mV AC, 500 μA AC, 50 mA AC, 5 A AC.
[3] 3 % in 500 mV AC, 500 μA AC, 50 mA AC, 5 A AC.

Input Characteristics

Overload
Function Input Impedance
[1]
Protection
 1000 V 10 MΩ <100 pF >120 dB at dc, 50 Hz or 60 Hz

[2]
1000 V 10 MΩ <100 pF >120 dB at dc, 50 Hz or 60 Hz
mV
10 MΩ <100 pF
1000 V

3.2 kΩ <100 pF

1000 V
Overload
Function
[1]
Protection
1000 V [2] 5 V dc
e
20 V decreasing
[2]
50e 1000 V
to 2.5 V
1000 V [2] 5 V dc

[1] Input is limited to the product of a V rms sinewave times frequency of 2 x 10
[2] For circuits <0.5 A short circuit. 660V for high energy circuits.
[1]
AC Bandwidth
15 Hz to 100 kHz
5 mV
25 mV
0.25 V
2.5 V
25 V
50 V
(rms sine wave)
15 Hz to 10 kHz
25 μA
250 μA
2.5 mA
25 mA
0.25 A
1.0 A
Nominal Response
[1]
Common Mode
Rejection Ratio
(1 kΩ unbalance)
>60 dB, dc to 60 Hz
(ac-coupled)
Not specified
(dc-coupled)
Open Circuit Full Scale Voltage
Test Voltage
To 500 kΩ ≥5 MΩ or 50 nS 500 Ω
550 mV
500 mV
3.1 V dc
Approximate DC
[2]
Trigger Levels
1 MHz 5 mV & 20 mV
1 MHz 20 mV & 60 mV
700 kHz 1.4 V & 2.0 V
1 MHz 0.5 V & 6.5 V
300 kHz 5 V & 40 V
300 kHz 5 V & 100 V
Approximate DC
AC Bandwidth
Trigger Levels
100 kHz
100 kHz
100 kHz
100 kHz
100 kHz
100 kHz
7 V-Hz product maximum). Noise at low frequencies and
7
V-Hz product) rms sine wave.
Accuracy
Specified accuracy ±12 counts for changes >425 ms in duration
in manual range.
Specified Accuracy ±40 counts for changes >1.5 s in duration in
manual range.
Specified accuracy ±100 counts
range) reading. For higher peak reading (to 12,000 counts),
specified accuracy ±2 % [3] of reading.
For periodic waveforms from 50 to 440 Hz ± (4 % + 1 count).
5 kΩ
<5 V 1 mA 100 μA 10 μA
7
V-Hz.
True-rms Digital Multimeters
Detailed Specifications
DC Bandwidth
600 kHz
1 MHz
80 kHz
1 MHz
300 kHz
300 kHz
DC Bandwidth
NA NA
[2] up to 5,000 counts (full
Normal Mode Rejection
>60 dB at 50 Hz or 60 Hz
>60 dB at 50 Hz or 60 Hz
Not specified
Typical Short Circuit Current
50 kΩ 500 kΩ 5 MΩ
1 μA 1 μA
10 mA
1 mA
[2]
50 MΩ 500 MΩ
0.3 μA 0.3 μA
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