Greetings everyone! I am currently designing a sensor array that will be used to detect the gases released by the durian. One of the sensors used is the SGX-4H2S-100 Industrial Hydrogen Sulfide (H2S) Sensor. From the datasheet, it says that the output signal is 1200+-250 nA/ppm. Thus, may I ask, with the circuit design shown below, am I reading the output value coming out of the sensor correctly?
The calculation of the 33k ohm is done as shown below:
From the datasheet, the output signal is 1200+-250 nA/ppm. So the maximum value of 1450 nA/ppm was used in the calculation. Other than that, the datasheet also shows that the measuring range is 0–100 ppm. Thus, the maximum concentration of gases that the sensor will be able to detect is 100 ppm. Then, the maximum output signal will be 145nA ( 100ppm*1450nA/ppm). Since the VDD of the ADS1115 is 5V, then the maximum ADC voltage able to be read by the ADS is 5V. Using Ohm's Law, V=IR , the calculated resistor value will be 34482.76 ohms. Thus, a 33K ohm resistor was chosen.
So my question is :
(i) Am I designing the circuit correctly?
(ii) Is there anything I need to take note of on the SGX-4H2S-100 datasheet?
The calculation of the 33k ohm is done as shown below:
From the datasheet, the output signal is 1200+-250 nA/ppm. So the maximum value of 1450 nA/ppm was used in the calculation. Other than that, the datasheet also shows that the measuring range is 0–100 ppm. Thus, the maximum concentration of gases that the sensor will be able to detect is 100 ppm. Then, the maximum output signal will be 145nA ( 100ppm*1450nA/ppm). Since the VDD of the ADS1115 is 5V, then the maximum ADC voltage able to be read by the ADS is 5V. Using Ohm's Law, V=IR , the calculated resistor value will be 34482.76 ohms. Thus, a 33K ohm resistor was chosen.
So my question is :
(i) Am I designing the circuit correctly?
(ii) Is there anything I need to take note of on the SGX-4H2S-100 datasheet?
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