Fluke 87 V/AN - Page 16

87 V/AN
Service Manual
8
Table 8. Frequency Counter Sensitivity and Trigger Levels
Minimum Sensitivity (RMS Sine wave)
Input Range
1
5 Hz - 20 kHz 0.5 Hz - 200 kHz
Approximate Trigger
Level
(DC Voltage Function)
600 mV dc
600 mV ac
6 V
60 V
600 V
1000 V
70 mV (to 400 Hz)
150 mV
0.3 V
3 V
30 V
100 V
70 mV (to 400 Hz)
150 mV
0.7 V
7 V (≤ 140 kHz)
70 V (≤ 14.0 kHz)
200 V (≤ 1.4 kHz)
40 mV

1.7 V
4 V
40 V
100 V
Duty Cycle Range Accuracy
0.0 to 99.9 % Within ± (0.2% per kHz + 0.1 %) for rise times < 1 µs.
1. Maximum input for specified accuracy = 10X Range or 1000 V.
Table 9. Electrical Characteristics of the Terminals
Function
Overload
Protection
1
Input Impedance
(nominal)
Common Mode
Rejection Ratio
(1 kΩ unbalance)
Normal Mode Rejection
L 1000 V rms 10 MΩ < 100 pF > 120 dB at dc,
50 Hz or 60 Hz
> 60 dB at 50 Hz or 60 Hz
F
mV
1000 V rms 10 MΩ < 100 pF > 120 dB at dc,
50 Hz or 60 Hz
> 60 dB at 50 Hz or 60 Hz
K 1000 V rms 10 MΩ < 100 pF (ac-
coupled)
> 60 dB, dc to 60 Hz
Full Scale Voltage Typical Short Circuit Current
Open Circuit
Test Voltage
To 6.0 MΩ
50 MΩ or
60 nS
600 Ω
6 k 60 k 600 k 6 M 50 M
e 1000 V rms < 7.5 V dc < 4.1
V dc
< 4.5
V dc
1 mA 100 µA 10 µA 1µA 1 µA 0.5 µA
G 1000 V rms < 3.9 V dc 3.000 V dc 0.6 mA typical
1. 10
6
V Hz max
Table 10. MIN MAX Recording Specifications
Nominal Response Accuracy
100 ms to 80 %
(dc functions)
120 ms to 80 %
(ac functions)
250 µs (peak)
1
Specified accuracy ± 12 counts for changes > 200 ms in duration
Specified accuracy ± 40 counts for changes > 350 ms and inputs > 25 % of range
Specified accuracy ± 100 counts for changes > 250 µs in duration
(add ± 100 counts for readings over 6000 counts)
(add ± 100 counts for readings in Low Pass mode)
1. For repetitive peaks: 1 ms for single events.