TB 9-6625-2331-35
IDENTIFICATION AND DESCRIPTION
1. Test Instrument Identification. This bulletin
provides instructions for the
calibration of Electronic Counter, John Fluke, Model PM6681/656. The manufacturer's
manual was used as the prime data source in compiling these instructions. The
equipment being calibrated will be referred to as the TI (test instrument) throughout
this bulletin.
a. Model Variations . None.
b. Time and Technique . The time required for this calibration is approximately 2
hours, using the dc and low frequency technique.
2. Forms,
Records, and
Reports.
a.
Forms, records and
reports required for
calibration personnel at all
levels are
prescribed by TB 750-25.
b. Adjustments to be reported are designated (R) at the end of the sentence in which
they appear. When adjustments are in tables, the (R) follows the designated adjustment.
Report only those adjustments made and designated with (R).
3. Calibration
Description. TI
parameters and
performance applications which
pertain to this calibration are in table 1.
Test instrument parameters
Performance specifications
Time base:
Aging rate (after 48 hour warmup): < 5 x 10-10 per day
Aging rate (after 24 hour warmup): < 1 x 10-8 per month
Aging rate (after 24 hour warmup): < 7.5 x 10-8 per year
Line voltage variation (for 10% variation): <5 x 10-10
Channel A and B sensitivity:
20 mV rms (-21 dBm), <100 MHz
30 mV rms (-21 dBm), 100 to 200 MHz
40 mV rms (-17 dBm), 200 to 250 MHz
60 mV rms (-11 dBm), >250 MHz
Channel C sensitivity:
20 mV rms (-21 dBm), 150 to 300 MHz
10 mV rms (-27 dBm), 300 to 2500 MHz
20 mV rms (-21 dBm), 2500 to 2700 MHz
Volt max/min
Range: -50 to +50 V dc
100 mV to 100 V pp (1 Hz to 100 MHz)
Accuracy:
(1% + 4 mV)
5 V dc (1X)
(2% + 40 mV)
50 V dc (10X)
(6% + 4 mV)
5 V pp (1X)
<30 MHz
(25% + 4 mV)
5 V pp (1X)
>30 MHz
(10% + 40 mV)
50 V pp (10X)
(5% of output level + 30 mV)
Trig level outputs