Product Introduction
1. Description of Small Infrared CO2 Sensor Safety Switch (NDIR CO2 Sensor Safety Switch) S8-4B:
Infrared CO2 Sensor Safety Switch (NDIR CO2 Sensor Safety Switch)S8-4BDuring normal operation, the sensor tests the CO2 gas concentration in the environment every 30 seconds. When the CO2 concentration exceeds 8000ppm, the sensor will issue an alarm signal. If any malfunction is detected, the error detection path will issue an alarm signal. The alarm filter protects the sensor from false alarms caused by intermittent interference.
The alarm output is the FET transistor drain open. During normal operation, the FET is off. Under alarm conditions, a low level is input to the drain, and the FET is in a conducting state. If the CO2 concentration is high, power consumption is low, or the sensor fails, any of these three conditions will trigger an alarm signal. Unless the CO2 concentration drops below 6500ppm or other alarm removal reasons occur, this output will remain in the alarm state.
2. Parameters of Small Infrared CO2 Sensor Safety Switch (NDIR CO2 Sensor Safety Switch) S8-4B:
| Item |
S8-4B |
| Target Gas |
CO2 |
| Operating Principle |
NDIR |
| Measurement Range |
400~2000ppm |
| Test Cycle |
30 seconds |
| Accuracy |
Between 7000ppm and 9000ppm alarm points, ±1000ppm |
| Operating Pressure Coefficient |
Deviation of 1kPa from normal pressure causes a 1.6% reading deviation |
| Response Time T90 |
2 minutes |
| Operating Temperature |
-5~60°C |
| Operating and Storage Humidity |
0~95%RH, non-condensing |
| Storage Temperature |
-40~70°C |
| Dimensions (mm) |
61 x 20 x 8.5 mm |
| Weight |
<10 g |
| Power Supply |
4.5~7V (not protected against surge voltage and reverse connection) |
| Power Consumption |
250mA max, 2mA average |
| Service Life |
5 years in typical indoor/office environments |
| Certification |
EN 61000-6-3:2007, EN 61000-6-4:2007 EN 61000-6-1:2007 RoHS directive 2011/65/EU |
| Alarm Output, Open Drain |
Open drain FET; 7V/800mA, protected by Zener diode, normally open, 100K ohm pull-up resistor connected to positive power supply 8000/6500 (alarm/release alarm) Normal state is open Transistor turns on at (CO2>8000ppm) or (non-load supply voltage <4.5V) or (load voltage <4V) or (sensor failure) |
| Maintenance |
Calibration (assumed at 400ppm CO2 concentration) |
| Self-diagnosis |
Full self-diagnosis at startup, continuous self-diagnosis during each test |
