Varian ProStar 340, Operation Manual

Page: 59 / 64

M
AINTENANCE AND
T
ROUBLESHOOTING
ProStar 340 UV/Vis Detector 33
Proper Full Scale Voltage Output
An exceptionally noisy baseline may also be due to an
inappropriate full scale voltage output setting for the strip chart
recorder. To test if the detector full scale output voltage is
properly configured:
1. Press the Short Switch and move the recorder pen to a good
reference point.
2. Release the Short Switch and press the Event Switch.
3. The event mark should be approximately 20% full scale if the
output voltage is properly configured.
4. If the event mark is too large, the output voltage needs to be
reduced.
5. If the event mark is too small, the output voltage needs to be
increased.
The instrument is factory configured to 10 mV full scale. To
change the full scale voltage:
1. Press the bottom half of Switch #3 so that it rocks downward
to the OFF position (see).
2. For a 100 mV scale output, press the top part of Switch #2
so that it rocks to the ON position (upwards).
3. For a 1.0 V full scale output, press the top portion of Switch
#1 so that it rocks to the ON position (upwards).
Filter Bypass Switch
An exceptionally noisy baseline not responsive to the Rise Time
Selector on the front panel may be the result of an activated
Filter Bypass Switch. When the Filter Bypass Switch is on, the
front panel rise time control is bypassed and a resultant rise time
of 0.1 seconds is created. To deactivate the Filter Bypass
Circuit:
1. Push the bottom half of Switch #6 (see Figure 7) until it rocks
downward to the OFF position.