Procedure to calibrate or recalibrate your WBO2 controller built-in to VEMS V3

These are included during v3 assembly. It can be useful for debugging if something is wrong. Check WBO2 + supply and other wiring (the most common mistakes).

wbo2_pump_pw_zero and wbo2_nernst_dc_target board calibration values are the results from these adjustments

Note: the following information is required for any WBO2 related question: wbo2 values (pump zero dutycycle, nernst dc target), controller serialnumber (preferrably also orderid), sensor resistance (Ohm measured between pin2 and pin6), acquired wbo2 calibration value.


Verify Pump-

Measure Pump+ and Adjust Pump-pw-zero

Verify Heater

Nernst-DC target

Quick Reference

DVM -DVM +Expected Val.Var to ChangeNotes
GNDpump-+4V (3.85-4.15V) Just verify
pump-pump+-4mV to +4mVpump_pw_zeroWBO2 off
pump-nernst+450mVwbo2_nernst_dc_targetWBO2 on