Sourcing thermometers and hygrometers from China

Zero duty

Read from the UK Trade Tariff on 25 September 2026, liquid-filled clinical and other thermometers, other thermometers and pyrometers including digital ones, barometers, electronic and other instruments such as hygrometers, and parts of heading 9025 carried 0% duty on goods from China, with no anti-dumping measure.

Thermostats and other automatic regulating instruments are in heading 9032, and infrared cameras in 8525; confirm the commodity code.

Mercury, medical and electrical rules

Annex II to the retained Mercury Regulation (EU) 2017/852 bans the manufacture, import and export of mercury-added non-electronic measuring devices, including thermometers, barometers, hygrometers and sphygmomanometers, with narrow exceptions. Liquid thermometers must use a non-mercury liquid such as coloured spirit or galinstan, and the supplier should confirm it in writing. For brewing instruments, see our brewing hydrometer sourcing guide. For dissolved oxygen measurement, see our guide to sourcing dissolved oxygen meters.

Thermometers sold to measure body temperature are medical devices under the UK Medical Devices Regulations 2002, so they need UKCA or CE marking, a UK Responsible Person for an overseas maker and MHRA registration; electronic clinical thermometers are tested to ISO 80601-2-56. Electronic thermometers and weather stations also need EMC conformity, battery and WEEE compliance, and wireless weather stations are radio equipment.

Worked duty example

Take a hypothetical order of 20,000 digital food probe thermometers, entered under 9025 19 00 90: £24,000 free on board plus £1,500 of freight and insurance gives a customs value of £25,500. Digital thermometers carry no duty, so import VAT of 20% on £25,500, £5,100, is the only tax. A VAT-registered importer normally reclaims it, so the border adds no lasting cost. Step by step: UK import duty and VAT.

Inspection checklist

Accuracy: readings compared with a reference thermometer calibrated by a UKAS-accredited laboratory at several points across the range, food and cold-chain thermometers checked against the requirements of BS EN 13485 where they are sold for chilled and frozen food, and hygrometers checked against saturated salt solutions or a reference hygrometer at a low and a high humidity point.

Electrical and radio: EMC evidence for the exact model to BS EN 61326-1 or the relevant product standard, wireless weather stations covered by ETSI EN 300 220 for short range devices and a declaration of conformity naming the Radio Equipment Regulations 2017, and button or AA cells checked for the right size and polarity marking.

Sealing and build: waterproof probes immersion-tested to the IP rating claimed under BS EN 60529, probe cables flex-tested at the strain relief, displays checked for missing segments at room temperature and after a spell in a freezer, and cartons sampled to ISO 2859-1 for English instructions and battery covers. For thermocouple models, see our guide to sourcing thermocouple probes. For resistance sensors, see our platinum resistance temperature probe sourcing guide.

What goes wrong

Thermometers fail on accuracy and sealing. Readings drift a degree or more from the stated tolerance because the sensor was not calibrated at the factory, humidity sensors saturate and stick at high readings, and probe cables break at the strain relief. Food probes that are not sealed let water into the housing after washing, and displays fade or fail in a freezer.

Check accuracy against a calibrated reference at several points across the range, such as an ice-point bath and a warm bath for food probes, ask for the factory calibration method and a sample of certificates, immersion-test waterproof probes to their claimed rating, flex-test probe cables, and at inspection check display segments, battery covers and the instructions in English.

Cambridge China Bridge sources food, room, clinical and weather thermometers and hygrometers, with calibration, mercury-free liquids and medical device paperwork agreed before the order. See how we source measuring instruments.