Stanford Research Systems SR620, Manual

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72 Calibration Procedure
SR620 Universal Time Interval Counter
12) Set the A slope to + and the B slope to - and
measure the time interval. Adjust calbyte 37
until the answer reads 0.
13) Set the A slope to - and the B slope to + and
measure the time interval. Adjust calbyte 38
until the answer reads 0.
14) Set the source to REF and attach the known
length cable from REF to B.
15) Set the A and B slopes to + and measure the
time interval. Adjust calbyte 32 until the
known value of the cable length is shown.
16) Set the A and B slopes to - and measure the
time interval. Adjust calbyte 35 until the
known value of the cable length is shown.
17) Set the A slope to + and the B slope to - and
measure the time interval. Adjust calbyte 33
until the known 500us is shown.
18) Set the A slope to - and the B slope to + and
measure the time interval. Adjust calbyte 34
until the known 500us is shown.
Rise/Fall Time Mode:
1) Set the mode to rise/fall time , arming to +
time. Set both A and B trigger thresholds to
the same value.
2) Set the source to A and attach the pulse
generator to A.
3) Set the slopes to + and measure the rise time.
Adjust calbyte 46 until the answer reads 0.
4) Set the slopes to - and measure the fall time.
adjust calbyte 47 until the answer reads 0.
5) Set the source to B and attach the pulse
generator to B.
6) Set the slopes to + and measure the rise time.
Adjust calbyte 48 until the answer reads 0.
7) Set the slopes to - and measure the fall time.
Adjust calbyte 49 until the answer reads 0.
Width Mode:
1) Set the mode to width, arming to +time. Set
both A and B thresholds to the midpoint of the
input signal.
2) Set the source to A .
3) Attach the non-inverting power splitter output
to A. Set the A slope to + and measure the
width. Write this down as W1.
4) Set the A slope to - and measure the width.
Write this down as W2.
5) Attach the inverting power splitter output to B.
Set the A slope to + and measure the width.
Write this down as W3.
6) Set the A slope to - and measure the width.
Write this down as W4.
7) Measure the period of the A input using a 1s
gate. Write this down as T.
8) Calculate the CHANGE to calbytes 41 and 42
as follows:
calbyte 41 change = (W1 + W3 -T)/
(2*2.7126736111E-12)
calbyte 42 change= (W2 + W4 - T)/
(2*2.7126736111E-12)
9) Repeat steps 1-8 with channel B to get the
changes in calbytes 43 and 44.
Frequency,Period,Phase,and Count mode:
1) These modes need no calibration.
D/A Output Calibration
Offset Calibration:
1) Attach a precision (better than 0.1% error) dc
voltmeter to D/A #0. Select the Scn submenu
of the configuration menus. Go to the d/a
mode line and set D/A #0 and D/A #0 to D/A.
Set D/A #0 to 0 V.
2) Adjust calbyte 16 until the meter reads within
5mV of zero.
3) Attach the voltmeter to D/A # 1. Set D/A #1 to
0 V.
4) Adjust calbyte 17 until the meter reads within 5
mV of 0.
D/A Output Gain Calibration: