Co Sensor Calibration Method - Renesas RL78/I1D User Manual

DETECT-IT RL78/I1D detector boards kit
Current measurement can be done at J1 and J2 jumpers, using an ampere meter.
The power consumption of each detector board is the sum of VDD current (measured at J1) and VDD_SENSOR current
(measured at J2).
So when you are doing current measurement, you should remove the jumper and place the ampere meter for doing your
measurement.
J1 and J2 should be then be in position for normal operation of the board with battery or with E1 connection (CN02
power). When measuring current at J1 for example, J2 jumper should always be in place, and vice versa.
9.2.3

CO Sensor Calibration method

The goal is to calibrate the following threshold: 100PPM CO concentration threshold calculation: Every CO sensor
canister is calibrated, with its calibrated value shown on each canister. For example in the following picture, the value
1425 is equivalent to 1.425nA/PPM. The threshold current for 100PPM is 0.1425µA.
The current-to-voltage conversion is 0.1425µA * 909K = 0.13V. Then change the code in user_main.c to the following:
If (adc_co > (adc_bias + adc_adiss * (0.1425*0.909/1.45))
Or
If (adc_co > (adc_bias + adc_adiss * (1425/15950))
UM-YDETECT-IT-RL78 V1.30
Figure Measurement for CO detector
Figure Calibration value shown on Figaro CO sensor
Kit User Manual
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