TSI Instruments Aerotrak 9303 - Instrument does not meet zero count specification (<1 particle;5 min).; Battery does not charge; Low Battery Indicator; Software does not connect to unit

2-22 AeroTrak
®
Handheld and Remote Airborne Particle Counters
6. Connect DVM across TP2 & TP5 on detector board. Set DVM to volts
DC. This will be used to measure the laser current (voltage across a
1 ohm resistor). Example: 0.075 volts = 75 mA.
TP2
TP5
7. Turn the potentiometer on the detector board counterclockwise
approx. five (5) turns.
8. Remove the two (2) Phillips head screws holding the laser board in
place.
C A U T I O N
The electronic circuits within this instrument are susceptible to
electro-static discharge (ESD) damage. Use ESD precautions to
avoid damage.
• Use only a table top with a grounded conducting surface.
• Wear a grounded, static-discharging wrist strap.