Quick answer: The current testo 110 is a single-channel contact thermometer for compatible NTC or Pt100 probes. Select the correct sensor for the material and temperature range, connect it securely, let the reading stabilize, then record the probe type and measurement point. Bluetooth and the testo Smart App can assist documentation on compatible current units.
Identify the testo 110 version and sensor
The current instrument (product number 0563 0110) supports NTC and Pt100 probes through its designated connection and can communicate with the testo Smart App. The probe is an essential part of the measuring system and is not interchangeable solely because a connector looks similar. An older testo 110 generation may have a different interface and accessories. For related guidance, see Testo Smart Probes Compatibility: Pairing Steps and Probe Selection.
Pt100 is commonly chosen for high-precision or extended-range applications where an appropriately specified probe is used; NTC probes are useful for many routine air, immersion and surface measurements. The probe specification determines the actual combined accuracy and permissible exposure. For a broader explanation of probe types and selection criteria, see the temperature probe selection guide.
Select the right contact technique
| Application | Probe approach | Main source of error |
|---|---|---|
| Liquid or soft material | Suitable immersion/penetration sensor | Insufficient depth or poor thermal mixing |
| Solid surface | Compatible surface-contact probe | Poor pressure, contact patch or conductive heat loss |
| Air temperature | Air probe located away from radiant heat sources | Radiation and local airflow distort the result |
| Laboratory reference check | Appropriate documented Pt100 probe | Assuming instrument range equals probe capability |
Make a reproducible measurement
- Identify the instrument version, attach the compatible sensor and inspect the cable and tip.
- Select a representative location and record ambient conditions that may affect the result.
- For contact surfaces, improve stable contact without damaging the probe; for liquids, immerse to the manufacturer’s specified depth.
- Wait for the temperature to approach equilibrium. Repeat at the same location if reproducibility matters.
- Use the display or compatible Smart App to document time, probe and sample ID.
Example: contact variation
Hypothetical: a pipe surface shows 31.4 °C on an initially loose contact and 34.0 °C after repositioning the sensor correctly. The difference is 2.6 °C. It demonstrates contact dependence, not proof that either reading is a traceable true pipe temperature. Compare consistently and use a purpose-designed pipe probe when required. For a dedicated approach to measuring pipe-surface temperature, see the testo 115i pipe temperature guide.
Bluetooth logging is not unattended monitoring
The app can display, store and document data while a supported connection is in use. Do not assume the handheld device continues autonomous multi-day recording after the phone disconnects. Where continuous monitoring and alarm delivery are required, choose a data logger designed for that role. For choosing equipment for longer-term monitoring, see the temperature and humidity data logger guide.
If two readings disagree
- Check whether the sensors are NTC versus Pt100 and whether each has the correct calibration data.
- Verify immersion depth, surface contact and response time before changing correction factors.
- Consider the measurement uncertainty of both device and probe; use a documented reference for formal verification.
- Do not claim a food-safe temperature or process acceptance threshold based only on an arbitrary contact reading.