Therma 20 Thermistor Food Thermometer

£73.00 ex VAT

£87.60 inc VAT
Therma 20 thermistor thermometer for high accuracy food temperatures

Probe not included

  • Assured accuracy for the life of the thermometer
  • Meets the European Standard EN 13485
  • Free traceable certificate of calibration included
  • UKAS 3-point certificate available*
  • 2-year guarantee
  • Biomaster product protection

Designed for catering applications where high accuracy is essential, the Therma 20 food thermometer is ideal for health and safety checks like HACCP

Add Accessories

Add calibration certificate (10-14 working days)

UKAS 3 point - instrument & probe (-18, 0, +70°C) *probe required for calibration

UKAS 3 point - instrument & probe (-18, 0, +70°C) *probe required for calibration

UKAS 5 Point Certificate - Instrument Only (-18, 0, +40, +70, +100°C)

UKAS 5 Point Certificate - Instrument Only (-18, 0, +40, +70, +100°C)

UKAS 5 point -instrument & probe (-18, 0, +40, +70, +100°C) *probe required for calibration

UKAS 5 point -instrument & probe (-18, 0, +40, +70, +100°C) *probe required for calibration


Add a probe

Add calibration add-ons

Add other accessories

Add probe wipes

Add cases, boots & holders

In stock
Product code: 226-040
Biomaster Protected Made in UK BRCGS

Therma 20 features

The Therma 20 thermometer's large digital display shows precise temperature measurements with a 0.1 °C resolution. It also features a wide temperature range of -39.9 to 149.9 °C, perfect for everyday catering checks.

Powered by three AAA batteries, this ergonomic cooking thermometer has an exceptional battery life of a minimum of five years. Additionally, the thermometer turns off automatically after ten minutes to maximise battery life.

Please note that next day delivery is unavailable if you choose a UKAS 3-point certificate with your order.

High-accuracy thermistor thermometer

The Therma 20 is perfect for food and catering businesses where accurate temperatures are critical. This high-accuracy cooking probe thermometer has a high system accuracy of ±0.4 °C, which is guaranteed for life due to the instrument's advanced electronics.


Choose from a FREE traceable calibration certificate or an optional UKAS 3-point certificate for additional confidence in this thermometer's accurate readings.

Compatible with a wide range of thermistor probes

The Therma 20 food thermometer can be used with any of our wired thermistor probes, enabling you to use the same instrument for multiple applications. Choose from colour-coded probes for avoiding cross-contamination, between-pack probes for monitoring cold food deliveries, and probes for many more daily safety checks.

Please note that the Therma 20 thermometer is supplied without a probe.

Handy food thermometer accessories

Adding a Therma Series Silicone Boot to your food thermometer will protect it against damage and make it splashproof to IP64. Use our Stainless Steel Wall Bracket to keep your Therma 20 stored safely and in an accessible location.

ISO EN 13485 is a European Standard of testing thermometers to ensure they're effective for monitoring the temperature of chilled and frozen foods during transportation, storage and distribution. The Therma 20 cooking thermometer is certified to this standard, which means you can be confident that your food thermometer is fit for this purpose.

Maintaining a hygienic cooking probe thermometer is essential for food businesses. The Therma 20 thermometer casing has Polygiene BioMaster antimicrobial technology to reduce bacterial growth.

To comply with regulations, food and catering businesses regularly verify their thermometers' accuracy. Validation checks couldn't be easier with our Thermistor Test Caps. Available in a range of temperatures, simply attach the test cap to the Therma 20 thermometer and check that the temperature on the screen matches the test cap.


The Therma 20 is designed and built by hand at our factories in Worthing, West Sussex. Supplied with a two-year guarantee, you can be confident that your food thermometer is built to last.


Product Details

Data sheet

Range:-39.9 to 149.9 °C
Resolution:0.1 °C
Accuracy:instrument only : ±0.2°C - system accuracy: ±0.4 °C (-24.9 to 109.9 °C)
Battery:3 x 1.5 volt AAA
Battery Life:minimum 5 years (20000 hours)
Sensor Type:thermistor
Display: 12mm LCD
Dimensions:25 x 56 x 128mm
Weight:130 grams
Case Material: ABS plastic includes Biomaster product protection
Country of Manufacture: United Kingdom
Guarantee: two years
Water/Dust Resistance: IP64 when using boot (optional accessory)
Measurement Scale: Celsius
Certification: FREE traceable calibration certificate
Conforms to Standard:EN 13485
Reviews (3)
226-040 C of C

226-040 Therma 20 certificate of conformity

Download (70.87KB)
ThermaCheck Therma 20 22 Inst

Instructions for ThermaCheck and Therma 20 & 22 thermometers

Download (241.47KB)

Sign in


My Wishlist0

Your cart

There are no more items in your cart