Figure 5-2. A3 Controller/Ref Board, Jumpers, Test Points, And Adjustment Locations - HP 5501B Operating And Service Manual

b. On A3, change the HEATER jumper from NRM to OFF. See Figure 5-2.
c. Apply power to the Digital Voltmeter and set its controls to the 1 Volt DC range. Connect
the positive lead of the Digital Voltmeter to A3TP11 then connect the negative lead to
A3TP1. See Figure 5-2.
d. If HP5501B power has been disconnected for least 2 hours, reconnect ±15 Volts system
power supplies and continue with the adjustment procedure in Paragraph 5-16.
5-16. Procedure to adjust the reference temperature, proceed as follows:
a. Check that the Voltmeter reads between +0.22V and +0.31V. This voltage is V(A3TP11).
b. Record value of V(A3TP11) measured in step 5-16(a).
c. Calculate the heater adjust set point using the following equation:
d. Vset = 1.285 x V(A3TP11)
e. Connect Digital Voltmeter plus lead to A3TP15. Connect the minus lead to A3TP1. See
Figure 5-2.
f. Check that the voltage at A3TP15 equals Vset ± 1 millivolt as calculated in step b. If not,
adjust A3R16 SET TEMP (see Figure 5-2).
g. Note and record the SET TEMP voltage in the "ADJUSTMENT RECORD" table located at
the end of this section.
h. Disconnect ±15 Volts from HP5501B Laser Head.
i. On A3, change the HEATER jumper back to NRM (left-most position). Remove the test
equipment leads, and reinstall the laser head covers.

Figure 5-2. A3 Controller/Ref Board, Jumpers, Test Points, and Adjustment Locations

HP5501B
Adjustments
5-3