Infrared CO2 Gas Detector 5100-88-IT

Infrared CO2 Gas Detector 5100-88-IT

Sierra Monitor’s 5100-88-IT detector monitors Carbon Dioxide (CO2), a toxic gas that is particularly dangerous in enclosed areas. This sensor monitors for adequate indoor air quality (IAQ) to ensure a healthy, comfortable, and productive work environment.

The 5100-88-IT detector is based on infrared (IR) technology, an accurate and stable method of detection that requires low maintenance and can operate in low oxygen environments and not be poisoned by toxic gases.

carbon dioxide and natural gas emission detector

As the release of Carbon Dioxide rises, it is important to install 5100-88-IT modules in facility ceilings and roofs. However, the result of installing the modules in high places requires more time and maintenance to calibrate them. With features such as non-intrusive calibration and remote sensor configuration, facility managers can calibrate and configure the module in hard to access areas without much effort. In addition, the 5100-88-IT only requires calibration at 1-year intervals, drastically reducing operating costs. Although the 5100-28-IT module can be used as a stand-alone sensor, it can also be used as a 4-20 mA component or as a Modbus RTU node. For higher level system capability, the module can interface directly to Sierra Monitor’s Sentry Controller to enable system level Modbus serial communications, area, and zone alarm management, extensive system diagnostic features, WebServer interface, and multiplexing sensor connections.


The 5100-88-IT supports GlobalCal™, our unique global calibration feature of the Sentry IT Controller. This allows a single technician to calibrate connected sensors from the Sentry IT Controller. With GlobalCal, the calibration happens at the controller level. Multiple sensors can be connected to a single controller, allowing groups of sensors to be calibrated at the same time. Standard gas is applied remotely, using permanently installed tubing, rather than direct delivery to the fixed gas detector.

Combined with the one-year calibration interval, GlobalCal reduces labor costs associated with calibration. The need to shut down active process areas for calibration consequently costs facilities thousands of dollars in lost production time. GlobalCal, with its remote and non-intrusive methods, allows production to continue during the calibration process, thus avoiding the costs of lost production. In addition, factory-authorized service technicians performing gas detector calibration save time and costs by remotely calibrating all gas detectors at once from the Sentry IT Controller.

GlobalCalTM support

Non-intrusively calibrate all connected sensors at the same time without declassifying the area

Network compatible with Modbus, 4-20mA, HART, relay interface

Easily install in a variety of field applications and easily obtain critical safety information wherever needed

Menu-driven system

Rapidly adjust user-friendly configuration of alarm setpoints, calibration, maintenance, and alarm acknowledgment

Modbus RTU Serial Interface

Provide an easy interface to the world’s most common industrial protocol

Integral LED Display

Easily calibrate and access gas concentrations, relay statuses, and diagnostics

SMC Sentry Digital Bus Interface

Connect easily with existing Sentry systems that have been in operation for many years

1 Year Calibration Interval

Dramatically reduce maintenance and operating costs for the user

Stainless Steel 316 or Epoxy-Coated Aluminum enclosures

Meet specific installation needs with different enclosure materials

Internal Continuous Self-Diagnostics

Automatically indicate any fault or optics problems

Remote Sensor Configuration

Remotely configure module for hard to access areas up to 100 feet away

Model Number


Sensor Type

Infrared, Dual Wavelength


Range: 0-5000 ppm Carbon Dioxide


Repeatability: +/- 1%


Accuracy +/- 2%


Sensor Life: Typically >5 years


Heated Sensor: Heat ed cell to prevent condensation


Response Time: T60 <20 seconds


Display: Fixed and scrolling LED

Signal Output:

3-wire Non-Isolated

4-wire Isolated

  • Sentry digital bus
  • Analog 4-20 mA

Serial RS-485 Modbus RTU

Relay: Optional



  • 5 amp Alarm, Warning (0.25 amp Trouble)
  • 5A @ 250 VAC, 5A @ 30 VDC (Alarm, Warning)
  • Board includes auxiliary connection for Sentry multiplexing


  • ermination board includes HART, MODBUS RS-485, 4-20 mA, Digital Input, 2A relay output, no Sentry bus

Power Consumption: 3 watts

Input voltage: 24 VDC nominal: 10-30 VDC

Operating Range

Ambient Temperature Range: -40o to 140°F (-40° to 60°C)

Relative Humidity: 0-99% Non-Condensing


Warranty: 2 years

  • Dimensions (H x W x D)
    • A1 & A2: 7.8 x 5.7 x 3.9 in. (19.8 x 14.5 x 9.9 cm)
    • S1 & S2: 7.5 x 4.4 x 4.9 in. (19 x 11 x 12 cm)
  • Weight
    • A1 & A2: 3.4 lb. (1.5 Kg)
    • S1 & S2: 7.2 lb. (3.3 Kg)
  • Enclosure: Epoxy coated aluminum or 316 stainless steel
  • Housing: AL or SS (same as enclosure)
  • Hazardous Area Classification:
    • Explosion proof, Class 1, Div. 1, Groups C, D
    • Class I, Zone 1
    • Group IIC, IP66, IP65, NEMA 4X, T6
    • TA = -40oC to 85oC II2 GD, Ex d IIC

Sentry IT Fire and Gas Detection Solutions

A brief introduction to the sales, design and manufacturing facilities for Sierra Monitor Corporation's Sentry IT fire and gas solutions.

How to Easily Calibrate Sentry IT Gas Sensors with GlobalCal

A video demonstration on how to perform GlobalCal, the simple and time-saving calibration procedure, on all Sentry IT gas sensor modules.