What are paired sensors?
Paired sensors are temperature sensors that are selected in the factory as a set because they produce almost exactly the same readings relative to each other. From a large batch of sensors only those units are chosen that exhibit identical measurement characteristics — within an extremely tight tolerance range. These sensors form a ‘pair’ and are then supplied as a set.
The great advantage: the sensors report the same, minimizing mutual differences. That makes paired sensors ideal for situations where the difference between two temperatures is more important than absolute accuracy.
Why use paired sensors?
Where a normal sensor can have a small deviation (e.g. ±0,3°C), paired sensors ensure this deviation is the same for both sensors. As a result they measure:
- synchronously
- consistently
- comparably
Without inaccuracies disturbing the measurement.
This is especially important in systems where a small temperature difference already has a large effect on:
- energy calculation
- control behavior
- efficiency
- reporting
Applications of paired sensors
Below are some practical situations where paired sensors really make a difference:
1. Delta-T measurement supply/return
A system measures the temperature difference between supply and return.
For example:
- Supply: 50,0°C
- Return: 40,0°C
- ΔT = 10°C
If the sensors are not paired, the measurement can become inaccurate due to individual tolerance differences. With paired sets the mutual deviation is virtually zero → exact ΔT.
2. Heat meter and energy meter installations (EN 1434)
Heat meters require the use of paired temperature sensors because energy calculations are extremely sensitive to deviations.
Applications:
- District heating networks
- Cooling installations
- Heat pumps
- Industry with energy data logging
3. Rooms with dual reference measurement
In large rooms or halls two sensors are sometimes used to:
- determine an average
- make the controller operate more stably
- prevent hunting
Paired sensors ensure that both measurements are equivalent.
4. Air handling: mixed air control
When outside air, return air and mixed air are compared, it is extremely important that all sensors have the same measurement behavior relative to each other.
Paired duct sensors prevent:
- incorrect mixing
- inefficient cooling/heating
- unstable control
Application areas
Paired temperature sensors are widely used in:
- HVAC systems
- Hydronic systems
- Heat pump technology
- Air handling units (AHUs)
- District heating networks and district heating
- Retail and commercial buildings
- Building management systems (BMS)
- Industry and process automation
- Energy monitoring systems
Difference from calibrated sensors
Paired sensors → mutually equal, for differential measurements
Calibrated sensors → individually accurate, for absolute values
These can complement each other, but serve a different purpose.
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