Combustion Flue Gas, Products, Testo

CO and CO2 monitor for ambient measurements – testo 315-3


“Cutting-edge technology, easy-to-use, rugged design. These are just a few of the features which make the testo 315-3 stand out head and shoulders above the rest. The CO and CO2 monitor is designed to measure carbon monoxide and carbon dioxide parallel in heating systems and ventilation ducts. The readings are presented on an easy-to-read display. A visual and audible alarm are activated when CO/CO2 thresholds are breached. The thresholds can be adjusted to suit your range of applications.

The intelligently designed monitor has an energy-saving lithium polymer rechargeable battery and powers off automatically when not in use.

And here’s yet another practical feature: the CO and CO2 monitor for ambient measurements can also be used in combination with the testo 330-2flue gas analyzer. The CO/CO2 reading scan be transferred directly to the analyzer via the meter’s infrared interface.

Tune up your CO and CO2 monitor with a range of accessories for even more possibilities

testo 315-3 is already well equipped to meet all the demands you would put on a CO and CO2 monitor. The following accessories are designed to allow you to customize your monitor to suit your own individual requirements:

– TopSafe protective casing: water and dirt repellent; provides testo 315-3 CO and CO2 monitor with protection in wet and dirty conditions

– Testo turbo printer: The testo turbo printer enables you to print out on site and provide with the necessary documentation. The results are transferred to the printer via the CO and CO2 monitor’s infrared interface

– Temperature/humidity module: allows you to carry out quick and reliable temperature and humidity measurements”

  • Parallel CO & CO2 measurement
  • Visual and audible alarm when thresholds are breached – adjustable thresholds
  • Extremely robust sensors
  • Conforms to the European Standard EN 50543 and British Standard BS 6173:2009
Delivery Scope

CO and CO2 monitor for ambient air measurements, USB power adaptor, cable


Download Datasheet Instruction manual

Application Image

Technical Details

Attachable humidity module – Capacitive
Measuring range +5 to +95 %RH
Accuracy ±2.5 %RH (5 to +95 %RH)
Resolution 0.1 %RH

Ambient CO₂
Measuring range 0 to 10000 ppm
Accuracy ±300 ppm (0 to 4000 ppm), 8 % of mv (4000 to 6000 ppm), 500 ppm (6000 to 10000 ppm)
Resolution 10 ppm

Ambient CO
Measuring range 0 to 100 ppm
Accuracy ±3 ppm (0 to 20 ppm)
±5 ppm (>20 ppm)
Resolution 0.5 ppm

Measuring range -10 to +60 °C
Accuracy ±0.5 °C (±1 Digit)
Resolution 0.1 °C

General technical data
Operating humidity 0 to 95 %RH
Dimensions 190 x 65 x 40 mm
Operating temperature 0 to +40 °C
Protection class IP40 acc. to EN 60529
Standards According to EN 50543
EU-/EG-guidelines 2004/108/EG
Interface IRDA / optional Bluetooth
Storage battery type Lithium polymer rechargeable battery
Battery charging option In instrument via mains unit
Battery charge In instrument via charger
Battery life 10 h measurement time (at +20 °C/+68 °F) / Mains operation possible
Storage temperature -20 to +60 °C
Weight 200 g