The Right Temperature Sensor for Every Application
Temperature is one of the most commonly monitored variables in building performance — and one of the easiest to get wrong. Sensor type, installation environment, wire run length, and the surface or medium being measured all affect accuracy and reliability. BluSENSE supports multiple temperature sensing technologies. Here's how to choose the right one for your application.
One-Wire Semiconductor Temperature Sensors
One-Wire sensors are our go-to recommendation for the vast majority of temperature monitoring applications — and for good reason. They combine low cost with excellent accuracy of ±0.2°C, and their communication architecture makes them uniquely practical for multi-point deployments.
Each sensor has its own factory-programmed serial number stored on an onboard microchip alongside its calibration data. That unique ID means up to 10 sensors can be daisy-chained on a single wire — one input, multiple measurement points, minimal wiring complexity. Communication uses a simple single-wire serial protocol that BluSENSE hardware reads natively. Output is typically 3.3–5V serial communication.
Unless your application has specific requirements that point elsewhere, the One-Wire sensor is the right choice.
Best for: General-purpose temperature monitoring, multi-point deployments, water temperature, ambient conditions, pipe surface monitoring
Not recommended for: Contactless or non-contact measurement applications
RTDs (Resistance Temperature Detectors), PT sensors, and thermoelements all operate on the same principle — their electrical resistance changes in response to temperature. Accuracy is among the best available across any sensor technology, which makes them the right choice when precision is the top priority.
The challenge lies in their output. Resistance changes translate to very small voltage signals — fractions of a volt — which makes accurate measurement more difficult, particularly over long wire runs or in electrically noisy environments such as mechanical rooms. In these conditions, signal interference can compromise the accuracy that makes these sensors valuable in the first place. Careful installation and shielded cabling are important considerations. Output is typically in millivolts or low volts.
Best for: High-precision applications, controlled environments, short wire runs
Not recommended for: Long cable runs, high-noise environments such as mechanical rooms without proper shielding
RTDs, PTs, and Thermoelements
Infrared temperature sensors measure the infrared light emitted by a surface to calculate its temperature — no physical contact required. Accuracy is excellent, and installation is straightforward: simply point the sensor's beam window at the surface or heat source you want to measure.
There are interferences to be aware of — reflective surfaces, ambient IR sources, and the emissivity characteristics of the target material can all affect readings. Understanding your specific installation environment is important before specifying an IR sensor. Output is typically I2C or a serial communication protocol, compatible with BluNODE.
IR sensors are available in two configurations. Single-point sensors measure temperature at a focused spot — ideal for pipe surfaces, equipment housings, and targeted heat sources. Array sensors use a grid of typically 8×8 infrared elements to either produce a crude 64-pixel thermal image of the field of view or calculate an averaged temperature across it. Arrays are particularly useful where a single-point reading would be unreliable — measuring the surface temperature of aerated water, for example, where infused air bubbles create an uneven thermal surface. The array captures the combined thermal signature across the entire field, producing a more representative measurement. Both types install the same way — non-contact, point and mount.
Best for: Surfaces that cannot be contacted directly, pipe exteriors, equipment surfaces, aerated or turbulent liquid surfaces where a single-point reading would be inconsistent
Not recommended for: Reflective surfaces without emissivity correction, applications requiring immersion or direct contact measurement
Infrared Temperature Sensors — Contactless