Manufacturer of Custom Temperature Sensors

Temperature & Pressure Solutions Made Easy
Phone: 800-284-3769 Fax: 858-573-0623

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Air Probes
Alumina Tubes
Autoclave Thermocouple
Carbon Dioxide
CO2 Transmitters
CO2 Handhelds

Cement On Thermocouple

Digital Thermometers
Extension Wire
Freezer Probe

Humidity Handhelds

Humidity Probe
Humidity Sensors
Humidity Transmitters

Mulite Tubes
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Panel Jacks
Partlow Controllers
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Pressure Transducers
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Protection Heads
RH Probes
Precision RTD Scanner
RTD Probes

RTD Data Logger
Surface RTD Probe
Surface Thermocouple
Surface Thermistor Probe
Temperature Calibrators
Temperature Transmitters

Thermocouple Strip Panel
Thermocouple Wire
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WIKA Pressure Transmitters
Validation Thermocouples
West Instruments


Carbon Dioxide (CO2) Measurement

Contact ThermX Southwest for Availability & Engineering Support.

GM70 Hand-Held
Lab Incubators
Harsh and Humid Environments
Air Quality
Carbon Dioxide Transmitter
Ecological Measurements
Carbon Dioxide Measurement
Carbon dioxide (CO2) is one of the most common gases in our atmosphere. It is formed during breathing of humans and animals, in fermentation and decomposition processes and during the burning of fossil fuels. Plants need carbon dioxide in the assimilation process. It can therefore be used as a fertilizer to enhance plant growth. Carbon dioxide is a good indicator for indoor air quality. In large concentrations carbon dioxide is a potential safety hazard and it inhibits bacterial growth.
  • Fixed Carbon Dioxide (CO2) transmitters
    Carbon Dioxide (CO2) transmitters for permanent wall and duct installations
  • Portable and hand-held Carbon Dioxide (CO2) meters
    Portable and hand-held humidity meters for spot measurements
  • Carbon Dioxide (CO2) probes and OEM modules
    Separately sold Carbon Dioxide probes and modules for original equipment manufacturers (OEM).
  • Calibrators
    Carbon Dioxide instruments for calibration and adjustment.


Vaisala CARBOCAP® Hand-Held Carbon Dioxide Meter GM70

The GM70 can be used in various spot-checking applications, like biomedical incubators, laboratories, greenhouses and mushroom farms. It is also suitable for HVAC applications. The meter can be used also as a calibration check instrument for the GM20 and GM220 Series fixed carbon dioxide instruments. The GM70 is compact and rugged, therefore an ideal choice for even the most demanding applications.
The GM70 incorporates the Vaisala CARBOCAP® Sensor, which enables reliable and stable measurement. It has two optional sampling methods: The handle is for diffusion sampling. The pump enables pump-aspirated sampling from locations difficult to access otherwise.The GM70 has a short warm-up time. The menu-based interface is easy to use and a graphical LCD display with data logger function provides an easy way to handle measurement data. A carrying case incorporates all the GM70 equipment and keeps the setup ready for immediate measurement.Technical specifications
Measurement range
Several options
from 0...2000 ppm to 0...20 %

± 0.02 %CO2 + 2 % of reading (GMP221)
± 20 ppm CO2 + 2 % of reading (GMP222)

Operating temperature
-20...+60 °C (-4...+140 °F)

Vaisala CARBOCAP® Carbon Dioxide Transmitter Series GMT220

The GMT220 series is for a wide range of industrial carbon dioxide applications including biomedical incubators, laboratories, greenhouses, fruit storages, safety alerts and demand-controlled ventilation in mushroom farms, livestock husbandry and parking garages. The GMT220 transmitters are designed to measure carbon dioxide in harsh and humid environments. The housing is dust and waterproof to IP65/NEMA4. The materials have been chosen for extended corrosion resistance.
The GMT220 transmitters are easy to use and install. The transmitters have a modular structure, which includes a separate mounting plate that eases the installation.Since the probes of the transmitter are truly interchangeable, they facilitate the field maintenance. The probes can simply be replaced with newly calibrated ones or with separate probes that are only used as a reference for calibration checking. This minimizes the downtime and eliminates the need for expensive calibration equipment.Technical specifications
Measurement range
Several options
from 0...2000 ppm to 0...20 %

± 0.02 %CO2 + 2 % of reading (GMT221)
± 20 ppm CO2 + 2 % of reading (GMT222)

Operating temperature
-20...+60 °C (-4...+140 °F)






Vaisala CARBOCAP® Carbon Dioxide Transmitter Series GM20

The GM20 series transmitters are specially designed for demand controlled ventilation and related applications. The transmitters incorporate the new silicon based Vaisala CARBOCAP® sensor. The simple structure and reference measurement capabilities make this Single-Beam Dual-Wavelength NDIR sensor extremely stable and reliable. Dust, water vapor or most chemicals do not affect the measurement accuracy of the sensor.
The GM20 transmitters are ideal for monitoring air quality in public, commercial and residential buildings. The transmitters are easy to install and require almost no maintenance (the recommended calibration interval is five years). Their use results in considerable savings in installation, operation, maintenance and recalibration costs as well as ensures the best possible control of air quality. The GMW20 series transmitters can be used independently or they can be incorporated into building energy management systems. The GMD20 is a duct-mountable transmitter. The wall-mount GMW20 is available in two sizes (GMW21 and GMW22). For the GMW21, an analogue temperature option is available offering active temperature measurement.Optional LonMark® approved interface modules are available for digital communication between the transmitters and a LonWorks network.Technical specifications
Measurement range
0...2000 ppm (nominal, can be calibrated for other ranges)

± 30 ppm + 2 % of reading

Operating temperature
-5...+45 °C (+23...113 °F)



Vaisala CARBOCAP® Carbon Dioxide Probe GMW115

Accurate and rugged probe-type field instrument for ecological measurements, such as:
- CO2 measurement range 0-2000 ppm
Building Energy Management Systems
- Ambient CO2 monitoring
- OEM applicationsKey features and benefits
-Compact, wall-mounted transmitter for demand-controlled ventilation
-Incorporates the Vaisala CARBOCAP® Sensor - the silicon-based NDIR sensor with unique internal referencing
Advanced single-beam dual wavelength measurement with no moving parts
Excellent long-term stability



Vaisala CARBOCAP® Carbon Dioxide Probe GMP343

Accurate and rugged probe-type field instrument for ecological measurements, such as:
- CO2 soil respiration
- Ambient CO2 monitoring
- Plant growth chambers
- OEM applications
Key features and benefits
- Diffusion-based design eliminates pumps
- Flow-through model also available
- Operates -40...+60 °C and 0...100 %RH
- Stable: 6 hour drift < 1 ppm outdoors
- Compensation options for temperature, pressure, humidity and oxygen
- Power consumption < 1 W
- Short warm-up time
- Small size and weight (0.4 kg)
- 5 measurement range options from 0...1000 ppm to 0...5000 ppm