MembersPage/GrmRacer/WbCal (2006-01-19 09:51:39)

This page is intended to document the actual method to WBo2 calibration for Vems 3.x process in one location in an easy to understand format for use with a windows box and MegaTune

Instructions for calibrating WBO2

These instructions are for bench calibrating your WBO2

There are two steps.


Calibrating pump_zero

This portion is a non-issue if you purchased a v3.3 and got an email with the pump_zero value in the email from the webshop.

You will be changing this value[ Highlighted box in MegaTune ]

Steps

[see photo] of the WBO2 connector [see photo]from the EC-18[photo] and measure the voltage. [Overall cartoon]

This voltage is "as close to zero as possible"


Free Air Calibration

Now that the pump_pwm_zero has been set you are ready to do the free air calibration. You will be changing the config.wbo2_calibration value [ TODO: Highlighted box in MegaTune ]

mde02 can also turn it on.

Manmlp07 shows output

changes for pump cal dont take effect until you reboot v3.x. The commanded current resolution is appr. Istep= 7mA / 256 = 27uA steps. Since we usually measure voltage (usually from pump- as base, not from GND), so the acceptable tolerance can be expressed in a voltage:

minicom in r30

Manmlp07mllbyebye

Man moves to comm mode

mlp07 switches to WBO2 related LCD-page

mll displays content (in terminal, so you can see even without real LCD)

byebye ends terminal mode and returns to megatune

I guess we should recommend a starting value (RCal=115 Ohm or so), and get the user read the O2% in free air. We make an O2%-reading => wbo2_calibration table which the user can look up => voila: WBO2 is calibrated in 1 step.