Display error messages
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© 2012 Thorlabs
2.2.8 Measuring the forward voltage (option PDA8000-FWD)
If the PDA8000 is used with the -FWD option the forward voltage (U
FWD
) of the
photodiode
can be measured at input 1. The measurement current (I
FWD
) used for
measurement can be selected in the range of 0.01 mA to 10 mA and is set by the
parameter:
Ifwd= 5.000mA
To measure the forward voltage (U
FWD
) select:
MEASURE Ufwd!
Then press the soft key
CHANGE
twice to do a measurement. The measured voltage
is displayed in the line
Ufwd=
2.3 Display error messages
Possible reasons for error messages when try to change parameters:
NOT IF BIAS
Attempt to change the polarity of the photo diode, the
measurement range or to start a forward voltage meas-
urement, while a bias voltage is applied.
POLARITY !
Attempt to apply a the bias voltage with wrong polarity
of the polarity of the photodiode.
Possible reasons for error messages during forward voltage measurement
ACCURACY !
Insufficient measurement accuracy (non-linearities or
noise)
OVERFLOW !
The requested forward current could not be reached,
even with the max. possible voltage. Possibly, no photo
diode connected or bad connection.
.
