TB 55-4920-428-35
11. SAS1 and SAS2 L V DT Voltages (Modified Circuit).
a. Performance Checks
(1)
Connect test equipment as shown in figure 3. Place TI controls as follows:
(a) SYSTEM SELECT to SAS1.
(b) FEEDBACK SELECT TO SELF.
(c) EXTERNAL METER SELECT to SELF FDBK.
(d) FUNCTION SELECT to CLSD LOOP.
(e) LINK TEST switch to SELF FDBK.
(2) Adjust the Wave-Tek Generator (A5) until the Digital Multimeter (A4) indicates .010 vac 0.001 vac. TI will indicate
0.0001 of the Digital Multimeter. If not, perform b below as shown in figure 4.
(3) Adjust Wave-Tek Generator until Digital Multimeter indicates between 0.95 and 1.05 vac and needle in the SAS1
Nullmeter points to the right.
(4) TI DVM willindicate the same as Digital Multimeter within 0.8% plus 6 counts maximum meter fluctuation. SAS1
Nullmeter wll indicate between 7.5 and 12.5.
(5) Adjust Wave-Tek Generator until the meter pointer on the SAS1 Nullmeter moves further to the right until decimal
point displayed on TI DVM just shifts one place to the right.
(6) Adjust Wave-Tek Generator until the Digital Multimeter indicates between 1.95 and 2.05 vac and needle in the SAS 1
Nullmeter points to the right.
(7) TI DVM will indicate the same as Digital Multimeter within 0.8% plus 6 counts maximum meter fluctuation. SAS 1
Nullmeter will indicate between 17.5 and 22.5 (needle points to right).
(8) Adjust Wave-Tek Generator until the Digital Multimeter indicates between 0.38 and 0.42 vac and SAS Nullmeter
indicates to the right.
(9) TI DVM will indicate within 0.8% plus 6 counts maximum meter fluctuation of the reading on the Digital Multimeter.
(10) Push the SAS X 10 meter button and observe that Nullmeter indicates between 35.0 and 45.0 (needle points to right).
Depress SAS1 X 10 meter button to obtain a Null reading on Nullmeter.
(11) TI DVM will indicate within 0.8 mv of the external DMM (with a maximum meter fluctation of 4 counts). The
external DMM will read less than or equal to 17 MVAC. The null meter will read 0 1 minor division.
(12) Repeat technique steps (2) thru (11) for the SAS2 meter circuit.
b. Adjustments. Adjust Null adjust R23 until TI DVM indicates within 0.0001 of the Digital Multimeter.
Change 3
23
