SRC-Q1T1 - Indoor


Indoor air quality (VOC) and temperature transmitter / monitor.

The SRC-Q1T1 is an indoor VOC (Volatile Organic Compounds) concentration and temperature measuring transmitter. Three LEDs in the colors green, orange and red indicate the air quality of the room air. This shows the user when to ventilate. The device has two analog outputs and one relay output.

The sensing element used is a MOS (metal oxide semiconductor) based gas sensor component. It is specifically designed for a broad detection of reducing gases such as VOCs (volatile organic compounds) and CO (carbon monoxide) associated with bad air quality. The sensor has to run at least 24h for reliable VOC values. It has the following features:
• Sensing range: 0 – 500 VOC index points
• High sensitivity and fast response
• Module with automatic baseline correction

The microprocessor samples the air quality once per second. It calculates an averaging signal over a preset number of samples and generates the output signal.
The analog output signal range may be customized by jumpers and if required by a programming module. Standard signal ranges are 0…10 VDC and 2…10 VDC. Other ranges can be defined by using the external display and programming module (OPA-S).


  • Indoor air quality and temperature measurement (home, office, school, restaurant, …)
  • Supervision of minimum and maximum VOC and temperature limits for critical environments
  • Direct control of extraction fan


  • Indoor air quality (VOC) and temperature measurement
  • Indication with three separate color LEDs
  • Minimum and maximum value memory
  • Two analog output signals for VOC and temperature values
  • 0…10 V or 2…10 V measuring analog output signal selectable with jumpers
  • Relay output indicating VOC concentration
  • Levels of VOC indication programmable
  • Automatic VOC background calibration
  • Output signal ranges programmable
  • May be used as simple P-controller
  • Averaging signal adjustable
  • Optional external display (OPA-S)
  • Status LED


 Product name  Product No.  Description
 SRC-Q1T1  40-300203  VOC + temperature transmitter / monitor



OPU-S - Remote Display
Operation and display for intelligent transmitters


Operation Manual

Install Sheet

Application Notes