User manual

Instruction Manual
ZDSERIES-GSM-REVA
25
B. LF Attenuation Accuracy
1. Disconnect the BNC tee at the power supply from the dual banana plug adapter.
Connect the BNC tee to the output of the function generator. (Use a 50 Ω
termination if the function generator requires such a load.)
2. Carefully insert the Straight Tips (supplied in accessory kit) into the sockets of the
probe head. Attach the red lead of the mini-grabber to the positive (+) signal
input and the black lead to the negative (-) input of the probe head.
3. Connect the BNC tee to the output of the function generator. (Use a 50 Ω
termination if the function generator requires such a load).
4. Attach a BNC cable to the unused female port of the BNC tee and connect a dual
banana plug adapter to the other end of the cable and plug the dual banana plug
adapter into the DMM input. Be sure the side of the banana plug adapter
corresponding to the BNC shield (marked "GROUND") is connected to the LOW or
COMMON input of the DMM.
5. Set the DMM to read AC volt and set the range to measure 5.0 Vrms.
6. Set the mode of the function generator to sine wave, the frequency to 70 Hz and
the output amplitude to 5 Vrms ±10 mV as measured on the DMM.
7. Record the output voltage to 1 mV resolution as "Generator Output Voltage" in
the Test Record. Be careful not to alter the output amplitude after the reading is
recorded.
8. Divide the reading recorded in step B-7 by the Effective Gain noted in step 6 and
record the result with 100 μV resolution as "Expected Output Voltage, top range"
in the Test Record.
9. Remove the banana plug adapter, connected to the function generator, from the
DMM and connect the precision 50 Ω terminator to the DMM, making sure that
the banana plug side marked "GROUND" is connected to the LOW or COMMON
input of the DMM.
10. After the DMM reading has stabilized, record the reading to 100 μV resolution as
"Measured Output Voltage, top range" in the Test Record.
11. Calculate the error by dividing the measured top range output voltage recorded
in step B10 by the expected top range output voltage recorded in step B-8.
Subtract 1 from this ratio and multiply by 100% to get the error in percent.
12. Record the calculated error to two decimal places (±0.xx%) as "Gain Error, top
range" in the test record.
13. Verify that the error is less than ±1.0 %.
14. Disconnect the precision 50 Ω terminator from the DMM.
15. Connect the banana plug adapter connected via a BNC cable to the BNC tee at
the function generator to the DMM. Verify that the side of the plug marked
’Ground’ is connected to the Low or Common input of the DMM.