Sensidyne / Products / Fixed Point Gas Detection / SensAlert IR Infrared Gas Detector

The fixed point Non-Dispersive Infrared (NDIR) LEL detector is designed for performance in harsh and hazardous Hydrocarbon gas environments. Utilizing solid-state infrared technology, this detector delivers dependable hydrocarbon gas detection with minimal maintenance requirements. The expected lifespan is 10 years.
Sensidyne provides a 2-4 week lead time – not 2-4 months!
Key Features:
High Reliability and Durability
The SensAlert IR has a straight-forward design and rugged 316 stainless steel sensor construction to withstand the most demanding applications.
No Routine Calibration and Virtually Maintenance Free
There is no scheduled calibration programs required for the operation of this instrument and required maintenance is limited to zeroing. You can practically “fire it and forget it,” except for normal periodic testing.
Operates in Anaerobic Atmospheres and Constant Hydrocarbon Background
The self-contained optics fully function in applications where there is no oxygen or hydrocarbons are regularly present. The SensAlert IR optics are also immune to poisoning and etching.
Dual Wavelength NDIR Technology
The sensing and reference elements are self-compensating for optical integrity
and other signal inhibitors.
Dual Infrared Sensors and Remote Mount Capability
One or two infrared sensors can be mounted locally or remotely up to 250 feet / 76 meters away from the transmitter.

Benefits:


Common Applications:
Class 1, Div-1 Rated Infrared Sensors for Combustibles –
316 Stainless Steel and Aluminum Enclosures:
General Purpose Area Infrared Sensors for Toxics –
Aluminum Enclosure:
NOTE: The SensAlert IR offers complete functional compatibility as a direct replacement for the discontinued Det-Tronics PointWatch® PIR9400 infrared gas detector. >>Read about it HERE.
Reach out to Our Expert Team for Tailored Safety Solutions and Technical Guidance.
Sensors
Types – Combustibles
Technology – Infrared
Detection Method – Diffusion
Min. Detectable Change – ± 1 %LEL
Repeatability – ± 2 % of reading
Accuracy – ± 3 % LEL, 0 to 50% LEL
± 5 % LEL, 51 to 100% LEL
Response Time (Rise) – T50 ≤ 5 seconds
T90 ≤ 10 seconds
Oxygen Requirement – None
Electrical
Power – 18-32 Vdc, measured at detector
5 Watts max
Termination Resistance – < 500 Ω @ 24 VDC
Outputs – 3-wire, 4–20 mA
User Interface
Controls – Zero
Interface – 4 mA level and activator
Environmental
Temperature – -40° to 158°F (-40° to 70°C)
Humidity – 0-99 % RH, non-condensing
Enclosure
Transmitter Material – Aluminum
Sensor Material – Aluminum / 316 Stainless Steel
Weight – 7 lbs (3.2 kg) / 10 lbs (4.5 kg)
Ingress – IP54
Approvals
NEC/CEC:
Class 1, Div. 1 Groups B, C & D
C22.2 No. 152-M1984
ISAS12.13.01-2000
Note: Refer to certification documents and datasheets for specific approval and configuration information.
1. What is NDIR sensor technology?
Dual Wavelength Non-Dispersive Infrared (NDIR) technology is a method used in gas detection sensors to improve accuracy and reliability. Here’s how it works:
This technology is especially valuable in industrial settings where consistent, maintenance-free, and accurate gas detection is critical.
2. What are the key advantages of using infrared (IR) gas detection over catalytic bead sensors for detecting combustible gases in this industry?
Infrared (IR) gas detectors, such as the SensAlert IR, offer several advantages over traditional catalytic bead sensors. IR sensors do not require oxygen to operate, making them ideal for enclosed or low-oxygen environments like cottonseed oil storage areas. They also have a longer lifespan, as they are not affected by sensor poisoning or degradation from exposure to combustible gas over time. Additionally, IR detectors require less frequent calibration and maintenance, reducing overall operational costs and downtime compared to catalytic sensors.
3. What are the maintenance and calibration requirements for SensAlert IR, and how does it minimize downtime?
The SensAlert IR is designed for low maintenance, requiring fewer calibration checks than traditional catalytic gas detectors. It features non-intrusive, local calibration, meaning safety personnel can calibrate the unit without needing to remove it from service. The system also includes self-diagnostic capabilities, which alert the user to any sensor drift or faults before they impact performance. With these features, downtime is significantly reduced, and maintenance teams can plan service intervals efficiently rather than reacting to unexpected failures.
4. Does SensAlert IR integrate easily with existing SCADA or control systems, and what communication protocols does it support?
Yes, SensAlert IR is designed for seamless integration with SCADA, DCS, and PLC control systems, making it a flexible solution for industrial safety managers. It supports industry-standard communication protocols, including 4-20mA analog output, HART, and Modbus RTU, ensuring compatibility with most modern monitoring systems. These interfaces allow real-time gas concentration readings, alarms, and diagnostics to be transmitted to a centralized control room. This enables facilities to remotely monitor gas detection status, improving response times and overall plant safety.
5. Is the SensAlert IR a good replacement for the discontinued PointWatch PIR9400?
Yes! The SensAlert IR offers form, fit, and function compatibility as a direct replacement for the discontinued Det-Tronics PointWatch® PIR9400 infrared gas detector. >>Read about it HERE.