Cummins/Onan GTA38 / GTA50 — Operating the Teledyne Model 320P / 320P-D Oxygen Meter
Operation · Service tool / oxygen meter
For the Cummins/Onan GTA38 / GTA50, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan GTA38 engine, Cummins/Onan GTA50 engine
Before you start
- Excess moisture or temperature in the sample will damage the O2 cell.
Procedure
- Read manufacturer's manuals for initial startup.
- Check battery condition before each use; recharge if low (overnight, 14 hours).
- Check filter material; change if wet or dirty.
- Calibrate with ambient air (20.9% O2); install flow-through adapter cap.
- Connect temperature reducing tubing to engine exhaust system.
- Coil tubing several times or make a dip to act as a water trap.
- Depress pump button to pull exhaust sample; draw no longer than 5 minutes.
- Clear the water trap every 10 minutes.
- After each 5 minutes sampling, purge with clean ambient air to near 20.9%.
- Turn off unit and reinstall cell saver cap when not in use.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Ambient air 20.9% O2
Source: Cummins/Onan owner's manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.