Are you visiting from outside your region? Visit your regional site for more relevant services and pricing.

Testo 315-3

Contact Instrument Solutions


The Testo 315-3 is an ambient carbon monoxide and carbon dioxide (CO and CO2) measuring instrument designed to meet the requirements contained in BS 6173:2009 and EN 50543. The measurement values can viewed directly on the large screen, printed directly using one of the optional printers, or transfered to the Testo 330 combustion analyser for subsequent analysis.

Instrument is available in two versions, with and without Blutooth capability which allows linking of the instrument to other devices, and various optional accessories such as a temperature / humidity probe and TopSafe case for the protection of the instrument during use.


The 315-3 instrument is fitted with a highly accurate electrochemical sensor for the measurement of CO and a shock resistant infrared sensor for CO2.

The instrument is fitted with a Lithium polymer rechargeable battery which gives a long life and it can be coupled with the auto-off feature to prevent unnecessary power use.


Storage temperature - 20 to + 60 °C

Operating temperature 0 to + 40 °C

Battery life (typical) 10 h

Weight 200 g

Dimensions 190 mm x 65 mm x 40 mm

CO gas cell type Electrochemical

CO cell measuring range 0 to 100 ppm

CO cell accuracy ± 3 ppm (0 to 20 ppm), ± 5 ppm (> 20 ppm)

CO cell resolution 0.5 ppm

CO2 gas cell type Infrared

CO2 cell measuring range 0 to 10.000 ppm

CO2 cell accuracy ± 300 ppm (0 to 4000 ppm), ± 8 % of mv (4000 to 6000 ppm), ± 500 ppm (6000 to 10000 ppm)

CO2 cell resolution 10 ppm

Optional temperature and humidity probe:

Temperature sensor type NTC

Temperature probe measuring range - 10 to + 60 °C

Temperature probe accuracy ± 0.5 °C (± 1 digit)

Temperature probe resolution 0.1 °C

Humidity probe type Capacitive

Humidity probe measuring range + 5 to + 95 % rh

Humidity probe accuracy ± 2.5 % rh (5 to 95 % rh)

Humidity probe resolution 0.1 % rh

Support documents

  • Download
  • Category
  • File type
  • Download
Testo 315 CO / CO2 analyser data sheet.pdf Testo 315 CO / CO2 analyser data sheet
Technical document
File type
Adobe Acrobat
Download (2 MB)
Testo 315-3 user manual.pdf Testo 315-3 user manual
Technical document
File type
Adobe Acrobat
Download (1000 KB)