Heat - Ventilation - Air Condition (HV-AC)

Sigma Hellas is offering instruments for HVAC & Refrigeration applications which include a wide range of portable contact and non-contact (IR) Thermometers & instruments for the measurement of:-

  • Temperature
  • Humidity
  • Air Quality (CO2, HC, CO)
  • Pressure
  • Air Velocity & Volume
  • Light level
  • Sound level
  • Speed (rpm)
  • Electronic Refrigeration manifolds
  • Data-loggers for the recording of Temperature,
  • Humidity and Analogue values (0-10V and 4-20mA).

see also the following categories in portable instruments for more information: flue gas, temperature, humidity, velocity, ultrasonic flow

Τhe needs and demands for indoor air quality monitoring are continuously increasing dramatically.
This in turn, has increased the demand for accurate measurements, instruments and sensors.

Air Quality & CO2 monitoring

model Sigma 95H with or without Sigma 1000H Controller

This state-of-the-art instrument measures carbon dioxide concentrations in the parts per million range.

Sigma 95H versatility is enhanced by options to satisfy most applications.

With an advanced technology Non-Dispersing Infrared (NDIR) sensor, Sigma 95H assures quick and reliable CO2 response.

Fresh air contains 350-400ppm CO2. Human respiration and combustion by-products from furnaces and household appliances can easily raise indoor levels above 2000ppm.

According to the National Institute of Occupational Safety and Health, increased levels of CO2 may contribute to 'Sick Building Syndrome' and symptoms such as hyperventilation, headache, dizziness, shortness of breath and drowsiness.

The 5000 is easy to install and support. Measurement output is via 4-20 mA current loop or a 0 to 10 volt interface. A completely isolated power supply eliminates any ground loop or electrical interaction problems when multiple units are connected to the same controller. Low power consumption makes the controller perfect for battery-operated or other power-sensitive applications.


Measuring range 0~2000 ppm CO2
0..5000 ppm CO2 0..10000 ppm CO2
Operating principle NDIR
Gas sampling method Diffusion or sample draw
Power supply 20-28VRMS AC, 18-30 VDC
Power consumption Less than 2W @ 24VAC
Response time Less than 1 minute
Repeatability +20ppm or 5% of reading
Operating humidity 0-90%
Operating temperature 0…..+500C (32…..+1220F)