Home » Discover » Sensors » SI-40-L


  • 4 Sensors: Temperature, Humidity, CO2, VOC
  • LonWorks (TP/FT-10) Network Communication
  • Software Capabilities: Set Point Adjustment, Override, Min/Max/Average Tracking
  • Selectable Display Screen Options

The simply elegant design of the SI-40-L sets a new standard in aesthetics and functionality to provide superior accuracy and performance, SAP™, for the sensing and control of Temperature, Humidity, CO2 and VOC. The aesthetic integrity of a building no longer has to be compromised to deliver optimum comfort and performance. Architects and designers can now work in harmony with engineers and contractors.

High performance cost effective sensing and control capabilities have been designed into the SI-40-L to provide an integrated solution for indoor air quality management. Optimum user functionality has been built into every SI-40-L to provide extensive information on the ambient conditions while implementing user-friendly displays for intuitive straight-forward operation.

Extensive data from the SI-40-L can be obtained through a LonWorks Free-Topology network connection. No additional connections are necessary to monitor individual sensors and track indoor air quality conditions.

Network Communication

Protocol: LonTalk™
Transceiver: FTT-10, Free Topology
Processor: Neuron™ FT6050, 80 MHz


Nominal Input Voltage: 24 VAC/VDC
Input Voltage Range: 21-28 VAC, 16-28 VDC
Typical Consumption: 4 VA
Maximum Consumption: 6 VA


Operating Temperature: -0 °C to +50 °C, 32 °F to 122 °F
Storage Temperature: -20 °C to 70 °C, -4 °F to 158 °F


Display Range: 0 to 50 °C (32 to 122 °F)
Accuracy: ±0.5 °C, ±1.0 °F


Display Range: 0.0 to 100.0 Percent
Accuracy: ±2% RH (10 to 90%)


Display Range: 0 to 2000ppm
Sensor:    Non-Dispersive Infrared (NDIR)
Accuracy: ±30ppm ±2% of measured value (25°C, 101.325kPa)
Repeatability: ±20ppm ±1% of measured value


Display Range: 0 to 10.0
Sensor:    Metal Oxide Semiconductor


Dimensions: L 5.14” x W 3.13” x H 1.04” (130.6 x 79.5 x 26.4 mm)
Material: ABS, UL 94-VO rated


Period: 2 Years (Limited)

SI-40-L – Model TH

On Board Temperature and Humidity Sensors

SI-40-L – Model TC

On Board Temperature and CO2 Sensors

SI-40-L – Model THC

On Board Temperature, Humidity and CO2 Sensors

SI-40-L – Model THCV

On Board Temperature, Humidity, CO2 and VOC Sensors


10000 St Clair Avenue

Fairview Heights, IL 62208


(618) 394-0300