LeCroy HFP1500, Instruction Manual

Page: 37 / 50

Performance Verification
HFP1500-OM-E Rev E
7–7
25. Remove the banana plug adapter from the DMM and connect the precision 50
Ω
termina-
tor to the DMM, making sure that the banana plug side marked ’GROUND" is connected to
the
LOW or COMMON input of the DMM.
26. Record the DMM reading to three significant places as ’Measured Positive Output Voltage’
in the Test Record.
27. Subtract the Measured Output Voltage as recorded in step B-26 from the Expected Out-
put Voltage recorded in step B-23. Be sure to include the sign of the values in the cal-
culation.
28. Record the result to 100 µV resolution as ’Offset Error Voltage’ in the Test Record.
29. Verify that the output error is between ±10.8 mV.
30. Return the oscilloscope offset to 0 Volt. Leave the setup connections for the next step.
C. 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. Disconnect the DMM from the precision 50
Ω
terminator and connect the DMM to the dual
banana plug adapter connected to the function generator output.
3. Set the DMM to read AC Volt and set the range to measure 5.0 Vrms.
4. Set the mode of the function generator to sine wave, the frequency to 70 Hz and the out-
put amplitude to 5 Vrms ±10 mV as measured on the DMM.
5. 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.
6. Divide the reading recorded in step C-5 by 10 and record the result with 100
µ
V resolution
as ’Expected Output Voltage, top range" in the Test Record.
7. 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.
8. After the DMM reading has stabilized, record the reading to 100
µ
V resolution as ’Mea-
sured Output Voltage, top range’ in the Test Record.
9. Calculate the error by dividing the measured output voltage recorded in step C-8 by the
expected top output voltage recorded in step C-6. Subtract 1 from this ratio and multiply by
100% to get the error in percent.
Error
Measured Output Voltage
Expected Output Voltage
-------------------------------------------------------------- 1
–
⎝ ⎠
⎛ ⎞
100%
×
=