daviteq Lidar People Counter, Руководство пользователя

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- Use the standard gas cylinder with a known concentration (for example Eythylene Air 1.35% is equivalent to 50 %LEL
) to supply the gas to the sensor;
- Use the calibration cap as above pictures to attach to the sensor and connect the tubing to the gas cylinder;
- Open the valve on the Cylinder slowly and make sure the gas has reached the sensor. The flow regulator should be
2.5LPM or 5.0LPM.
- Press a timer to start counting the time;
- After 2 minutes, force the device to send data once every minute, and stop forcing at 5 minutes ;
- The highest Raw_value is the Span value.
- After that, immediately turn OFF the valve to save the gas;
- Remove the calibration cap from the sensor;
- Place the sensor in clean air again.
-The calculation of new A, B value based on basic linear formula: y = A * x + B
Where:
A, B is calibration coefficients
x is the sensor process value (example gas level in ppm) read on reading device such as on application server/network
server, on offline tool. The process value is the RAW_VALUE in the payload
y is the correct value. y is the value of standard gas/standard condition
Which condition of Zero value: y
0
=A * x
0
+ B
Which condition of Span value: y
s
=A * x
s
+ B
From the two formulas, the calculation of A, B as below
A = (y
0
- y
s
) / (x
0
- x
s
)
B = (y
s
* x
0
- y
0
* x
s
)/ (x
0
- x
s
)
-Example of A, B calculation for LoraWAN Ammonia Gas sensor (item code WSLRW-G4-NH3-100-01):
* With condition of clean-air environment at a temperature from 20 - 30 oC, there is no ammonia gas (y
0
= 0); while
the NH3 level on reading device (RAW_VALUE in the payload) is -0.25 (x
0
= -0.25)
* When the sensor is connected to standard gas cylinder having ammonia level of 25 ppm (y
s
= 25); while the NH3
Note: Keep the sensor Power ON all the time;
Notes:
- The tube length is short as possible to reduce the gas loss;
Note: just get one value for Span
Note: Always keep the sensor Power ON all the time;
Step 3: Calculate the new A and B