Testo 115i Pipe-Clamp Thermometer

The Testo 115i is a pipe-clamp thermometer in the Testo Smart Probes family, built for reading suction and liquid line temperatures on air conditioning, heat pump, and refrigeration systems. An NTC sensor sits in a spring clamp that fits pipes from 0.25 to 1.5 in. in diameter. The probe has no display of its own and sends readings over Bluetooth to measureQuick or the testo Smart App. This listing covers the current second-generation probe, which Testo rates for a Bluetooth range of up to 350 ft.

Pipe Temperature Measurement

The 115i reads from -40 to 302 °F (-40 to 150 °C) at 0.1 °F resolution, once per second. Testo rates its accuracy at ±2.3 °F (±1.3 °C) from -4 to 185 °F (-20 to 85 °C), a band that covers the suction and liquid lines of a typical comfort cooling system. A clamp reads the pipe wall, so clean copper and full contact between the sensor and the pipe keep the reading close to the refrigerant temperature inside.

measureQuick Wireless Integration

The 115i connects to measureQuick over Bluetooth alongside the other Testo Smart Probes on the job. Paired with a 549i pressure probe on the same line, it gives measureQuick what it needs to calculate superheat on the suction line or subcooling on the liquid line, so two 115i and two 549i probes cover both sides of the system. Line temperatures go into the test record with no hand transcription, recorded with the airflow, static pressure, and psychrometric readings from the same test.

Build and Field Readiness

The 115i measures 7.2 x 3.5 x 1.2 in. and runs about 150 hours on three AAA batteries. It operates from -4 to 122 °F (-20 to 50 °C), ships with batteries and a calibration certificate, carries a 2-year Testo warranty, and fits the Testo Smart Case (Refrigeration) with the rest of the refrigerant-side Smart Probes.