Gravity: Factory Calibrated Electrochemical Oxygen / O2 Sensor (0-25%Vol)

1. Getting Started

This article outlines critical guidelines for handling and installing sensor modules, emphasizing precautions for optimal performance and avoiding damage.

2. Example Code for Arduino-Acquire data in initiative mode

In this routine, the sensor will actively return data once a second, and the controller will receive and parse the data. Users will learn how to configure the sensor for initiative mode and read data automatically.

3. Example Code for Arduino-Acquire data in passive mode

In this routine, the controller needs to request data from the sensor every time, and then the sensor returns the data. Users will learn how to connect the sensor to Arduino and read gas concentration, gas type, and board temperature in passive mode.

4. Example Code for Arduino-Threshold alarm function

In this routine, users will learn how to set a threshold alarm for the gas sensor. When the gas concentration exceeds the set threshold, the ALA pin will output a high level, and a warning message will be printed to the serial monitor.

Reference

Specification

Parameter	Description
Detection Gas	CO, O₂, NH₃, H₂S, NO₂, HCl, H₂, PH₃, SO₂, O₃, Cl₂, HF (different probes required)
Working Voltage	3.3–5.5 V DC
Working Current	< 5 mA
Output Signal	I²C, UART output (0–3 V), analog voltage (depending on probe characteristics)
Detection Error	±10% of output value or ±5% of full scale (whichever is greater)
Working Temperature	−20 °C to 50 °C
Working Humidity	15–90% RH (non-condensing)
Storage Temperature	−20 °C to 50 °C
Storage Humidity	15–90% RH (non-condensing)
Lifespan	> 2 years (in air)
Adapter Plate Size	37 × 32 mm
Operating Pressure Range	0.5–2.0 bar

Characteristic Parameters

SKU	Type	Detection Range	Resolution	V0 Voltage output range	Vout1	Response Time（T90)
SEN0465	O2	(0-25)%Vol	0.1%Vol	(1.5-0)V	1.0V@10%vol	≤15S
SEN0466	CO	(0-1000)ppm	1ppm	(0.6-3)V	0.9V@200ppm	≤30S
SEN0467	H2S	(0-100)ppm	1ppm	(0.6-3)V	1.5V@50ppm	≤30S
SEN0468	Cl2	(0-20)ppm	0.1ppm	(2-0)V	1.3V@10ppm	≤60S
SEN0469	NH3	(0-100)ppm	1ppm	(0.6-3)V	1.4V@50ppm	≤150S
SEN0470	SO2	(0-20)ppm	0.1ppm	(0.6-2.4)V	1.5V@10ppm	≤30S
SEN0471	NO2	(0-20)ppm	0.1ppm	(2-0)V	1.2V@10ppm	≤30S
SEN0472	O3	(0-10)ppm	0.1ppm	(2-0.7)V	1.3V@5ppm	≤120S
SEN0473	H2	(0-1000)ppm	1ppm	(0.6-3)V	1.3V@500ppm	≤120S
SEN0474	HCL	(0-10)ppm	0.1ppm	(2-0.7)V	1.4V@5ppm	≤60S
SEN0475	HF	(0-10)ppm	0.1ppm	(2-0.5)V	1.3V@5ppm	≤60S
SEN0476	PH3	(0-1000)ppm	0.1ppm	(0.6-3)V	0.7V@50ppm	≤30S

Explanation of VO use:
VO: It means original voltage (linear) after amplifying circuit, rather than concentration value of current environment.

Calculation method: concentration in the current environment N= 200/(Vout1-Vout0)*(Voutx-Vout0)

Where Vout1 corresponds to Vout1 in the table and Vout0 corresponds to the voltage value of the gas at 0 ppm in the table. Take CO as an example: zero point voltage Vout0 = 0.6V, Vout1 = 0.9V, the current voltage of VO Voutx = 1.2V, then the current concentration in the environment N = 400ppm

The analog output is the original uncalibrated voltage of the probe, the UART/I2C data is factory calibrated, if there is no special requirement, it is recommended to use the calibrated UART/I2C data.

Pinout

Board Overview

Smart Gas Sensor Terminal Pinout

Label	Name	Function description
1	D/T	I2C data line SDA / UART data transmitting-TX
2	C/R	I2C clock line SCL / UART data receiving-RX
3	-	GND -
4	+	Power supply + (3.3-5V compatible)

Additional Pinout

Label	Name	Function description
1	VCC	Positive power supply (3.3-5V compatible)
2	GND	GND negative power supply
3	V0	The raw voltage output of the gas probe. You can develop your own conversion algorithm based on the original output.
4	ALA	Threshold alarm function, the threshold can be set through API, when exceeding this value, the pin will output high level.
5	NA	Reserve custom pins, you can contact us for custom functions.