Table of Contents
Problems and Solutions
Problem
The PCASP pump would not turn on while in the PMS can on the aircraft.
Cause
The 1D card was not able to switch the pump on through the M300.
Solution
Hard wire the pump to turn on when the probe turned on. The jumper wire went from the positive pump control to the the ground of a reference channel to complete the circuit. In N555DS the wire goes from the Left wing silver pylon on the cabin data box P2 and jumps between pins 20 & 17. The wiring diagram is now on the N: Drive (PCASP_PumpHardWire_Aircraft).
Problem
The PCASP did not size particles in the correct channels. With 800 nm, 900 nm and 2000 nm beads there were no peaks near the correct channel.
Cause
The inlet was not aligned correctly.
Solution
Remove the inlet deceleration section. Turn the small needle like inlet tube until the number concentration was the largest in the correct channel. Specially, generate particles of known size and direct them onto inlet while turning the inlet until the maximum concentration is detected. See picture below.
Problem
No particle size information from the PCASP
Cause
The cards had been replace by incorrect cards, and several of the cards had issues.
Solution
SEA worked on the figuring out the right cards and fixed the electrics on many of them.
Problem
The pump in the pcasp is not turning on.
Cause
One possible cause was bad relay. Another possible cause is incorrect software switch.
Solution
A new relay (solid state relay-Newark p/n 93k7598, Crydom - model S228) was ordered and installed. The PCASP was bench tested and determined to work fine.
Problem
During the 2015 CAPE project in Florida, the PCASP voltages would change from the normal value of >6.5 to ~ 3 volts. The concentration seems to change corresponding to the voltage change. Need to look into this since the laser may be failing.