NOA Detector Problems

A list of possible problems with the chemiluminescence detector appears below. If the problem is not listed below or assistance is needed, contact GE Analytical Instruments.

NOA fails PMT test (280i) or E04 ozone test (280). For Firmware version 3.0 (280i) PMT signal can be viewed in Status screen and should be < 100 counts.
Possible Causes Action Required
Light Leak If reaction chamber was just cleaned, o-rings may not be in proper position or Allen screws not tight. Check that o-rings are properly seated and fully tighten Allen screws
  Turn off room lights and start NOA. After NOA passes test, use a flashlight to determine source of light leak (reaction chamber, vacuum hose).
No or low flow into NOA Disconnect filter line from purge vessel to frit restrictor and try to start NOA.
PMT temperature too high Wait at least 30 minutes after turning on NOA power before trying to start NOA.
Dirty reaction chamber causes small signal from ozone decomposition Connect NO cal gas to NOA then try to start. If cal gas not available, nasal NO can be used by holding tubing near nose and exhaling through nose. If NOA starts with high NO, try cleaning reaction chamber.
Blown ozone fuse Check ozone fuse on back panel (NOA 280) or inside NOA 280i (back right-hand side) and replace if necessary.
Electronics problem Contact GE Analytical Instruments

E 02 — Cell Pressure was Above the Limit
Possible Causes Action Required
Pump off Set pump power switch to ON, check power cord from NOA to pump.
Leak Check vacuum hose and connections for NOA and trap.
Problem with pump Contact GE Analytical Instruments

E 03 – Ozone Supply Pressure was Below the Limit
Possible Causes Action Required
Oxygen Tank off or outlet pressure low Turn on the oxygen supply and adjust outlet pressure or flow
NOA regulator set too low Adjust NOA regulator
Bad regulator or pressure transducer Contact GE Analytical Instruments

E 05 – Cooler Temperature Above the Limit
Possible Causes Action Required
Insufficient time to reach temperature Wait 30 minutes after turning on NOA power for cooler to reach temperature
Blown Cooler fuse-fan off (NOA 280 only Check back panel cooler fuse
Loose electrical connection

NOA 280 – remove top cover and verify red wire is connected to blank transformer and black wire is connected to spade type plug.

NOA 280i – verify cooler is connected to power supply board

No Power to NOA
Possible Causes Action Required
Blown fuse Remove NOA power cord, open power entry module and check fuse, replace if necessary

No AC to detector

 Confirm the outlet is supplying AC by connecting another device

No Display but fans are on
Possible Causes Action Required
Blown fuse on power supply board Unplug NOA, remove top cover and check fuse on power supply board, replace if necessary
Contrast out of adjustment Locate the Contrast Adjustment on the Digital Board (small white screw near bottom, right corner of board). Turn the NOA Power on and use a small screwdriver to turn the contrast adjustment screw while viewing the LCD display. Adjust the screw to give a clear display.