Sourcing ultrasonic level sensors from China

Duty and classification for liquid-level sensors

Heading 9026 covers instruments measuring or checking liquid or gas variables, including liquid level. Electronic ultrasonic liquid-level sensors are candidates for 9026 10 29 00. The comparison rows cover other level instruments, other electronic instruments and parts; they are not interchangeable classifications for a complete ultrasonic sensor.

Read from the UK Trade Tariff on 18 October 2026, the listed lines carried 0% duty for goods from China, with no anti-dumping or countervailing duty, suspensions or attached controls recorded. Mercury controls recorded against pressure-instrument lines do not appear against these selected lines.

Confirm the commodity code using the complete product description, measuring function and whether the shipment contains finished instruments or parts. See the wider flow meters and pressure gauges guide for other instruments in this heading.

Specify the tank, liquid and signal

Give the factory the tank drawing, mounting position, liquid, operating temperature and expected vapour, foam or agitation. Agree the measuring range, blind zone beneath the sensor, beam clearance and required accuracy. State whether the display reports distance, liquid depth or calculated volume, and supply the tank geometry if volume is required.

Specify the supply, output signal, cable entry, mounting thread or flange, enclosure protection and behaviour when an echo is lost. For apparatus within electromagnetic compatibility rules, the importer must check the manufacturer's conformity assessment and provide importer identification and a postal address on the equipment, or where that is impossible, its packaging or accompanying documentation.

For potentially explosive atmospheres, confirm the applicable equipment regulations with the relevant authority. Match the declaration, equipment category and any required certificate to the actual model and marking before ordering.

Worked duty example

Illustrative example, not a quote: Illustrative order of 800 ultrasonic liquid-level sensors under 9026 10 29 00, invoiced at £96,000 free on board, with £3,500 of freight and insurance to the UK. The customs value is £99,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £99,500, so it is £19,900. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Readings: compare displayed level and transmitted output with measured liquid depth across the agreed range, including near the blind zone.

Echo behaviour: test the agreed mounting arrangement with representative foam, agitation and obstructions; check lost-echo indication and recovery.

Connections: check mounting dimensions, seals, cable entries, terminal identification and output compatibility against the approved sample.

Documents: match model and serial identification to calibration records and conformity documents. Use inspection to record the readings and defects before release.

What goes wrong

A sensor can work over an open test container but give unstable readings in the buyer's tank. Foam, condensation, agitators and nearby walls can weaken or redirect echoes. A mounting position that places the normal liquid surface inside the blind zone can prevent useful measurement.

Incorrect tank geometry produces wrong volume readings even when distance measurement is accurate. Reversed output scaling, unsuitable seals and undocumented lost-echo behaviour can also cause commissioning problems. Agree a representative tank test and acceptance criteria before approving bulk production.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For components and parts, see sourcing for manufacturers.