If the manufacturer has no calibration then you go back to the AWB and it tells you to calibrate the gauge each 12 months.
At what pressure is this voltage calibration done?
How do you know it is 125 psi if the gauge is not calibrated?
You will find that data generated by a AMO is approved by CAsA or a Aeronautical Engineer - it certainly was not a gift when I got my AMO nor is it in REG 2a - unless I (AMO) make the spark plug tester and produce my own calibration data.
But then it is approved data by being manufacturer not a AMO!
No I don't work for CAsA. I still hold a AMO so I don't think being an employee of CAsA is allowed.
Tester Calibration
• Set a new RJ12YC to 0.035”
(0.9mm) gap.
• Install plug in the pressure chamber,
increase the pressure until indicator
needle reaches 125 psi.
• Adjust the voltage control on the
bottom of the electronic control
module just until the arc is extinguished.
The unit is now properly calibrated for
all plug testing.
NOTE: Champion recommends this
calibration procedure at least once a year.