Philips PM 6670 Operating Manual page 20

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Push DISPL HOLD. The counting should stop.
Release DISPL HOLD. The counting should start from
the accumulated value.
Count 10® pulses (takes approx IDs) and press
DISPL HOLD, the decimal point to the right of the
6:th decade should light. The ms/MHz LED should
also light, indicating that the result should be multi
plied by 10®
Push RESET and release DISPL HOLD.
Check of COUNT A Gated by B
Note: The instructions for checking Count, Puise Width
and Time Interval are written in such a manner that
the checks should be made in sequence.
• Select COUNT A Gated by B -J 1—
• Connect 10MHz OUT from e.g. a PM6650 to input
A and TIME-BASE OUT to input B. The PM 6650
should be set to PERIOD A with a 1 us time base.
• Release CHECK.
• The display read-out should be 6.
• Push SLOPE for input B. The display read-out should
be 4.
• Release SLOPE for input B.
Check of COUNT A Start/Stop by B
• Select COUNT A. Start/Stop by B -Tl—H—
• The display read-out should be 10. Push SLOPE
for input A if necessary due to the internal phase
condition in the LSI counter-ona-chip.
• Release SLOPE for input A.
Check of PULSE WIDTH A
• Select PULSE WIDTH A.
• Remove the cable from input A. Shift the cable from
input B to input A.
• The display read-out should be 0.0006 ± 0.0001 ms.
• Push SLOPE for input A. The display read-out should
be 0.0004 ±0.0001 ms.
• Release SLOPE for input A.
Check of TIME INT SINGLE A-B
• Select TIME INT SINGLE A-B.
• Push COM via A and SLOPE for input B.
• The display read-out should be 0.0006 :
• Push SLOPE for input A and release
input B.
• The display read-out should be 0.0004 ± 0.0001 ms.
0.0001 ms.
SLOPE for
Check of RPM
• Select RPM A.
• Connect a 50Hz, 500mVpp square-wave to input A.
• The display read-out should be approx 3000.
Check of PERIOD A, FREQ A
and RATIO A/B
• Select required function and push CHECK.
• Adjust the measuring time and check the display
read-out as follows.
MEAS.
TIME
1 0ms
100ms
Is
PERIOD A
100.000ns
100.0000ns
100.00000ns
FREQ A
10.0000MHz
10.00000MHz
10000.000kHz
RATIO A/B
1.00000
1.000000
1.0000000
• Release CHECK.
Check of PHASE
• Select PHASE A-B. Push COM via A and SLOPE
for input B.
• Connect a 1.6MHz, 10OmVpp sine-wave to input A.
• The display read-out should be 1 8Cf± 3° .
• Push SLOPE for input A and release SLOPE for
input B.
• The display read-out should be 1 80°± 3° .
• Release SLOPE for input A.
Check of HOLD OFF
• Select TIME INT SINGLE A-B and push SLOPE for
input B.
• Connect a 50Hz, lOOmVpp square-wave to input A.
• The display read-out should be 1 0ms.
• Turn the HOLD OFF potentiometer slowly clockwise,
until the display read-out is 30ms.
• Push CHECK. The Hold-Off time should be approx
1 0ms.
• Reset HOLD OFF to 0. Release COM via A, SLOPE
for input B and CHECK.
Check of the low-pass filter
• Push the 50kHz FILTER button.
• Connect a 1MHz sine-wave to input A. Check that
the counter requires a signal amplitude ± 40dBm
(20x) higher than without filter.
Check of TIME INT AVERAGE A-B
• Select TIME INT AVERAGE A-B.
•Set the measuring time to Is. The display read-out
should be approx 400ns.
•Release SLOPE for input A and push SLOPE for
input B. The display read-out should be approx
600ns
• Remove the cable from input A.
Check of the dead-time between
stop and start
• Select PULSE WIDTH A.
• Push COM via A and SLOPE for input B.
• Connect a pulse generator to input A and adjust
the output to 1 MHz with 0.8V amplitude.