Due to different application fields, forTemperature and humidity sensorThe technical requirements are also different. From a manufacturing perspective, the same temperature and humidity sensor has different materials, structures, and processes, resulting in significant differences in performance and technical indicators, and therefore prices. We can choose from the following aspects:

1) Select measurement range:
Like measuring weight, temperature, and humidity, choosing a temperature and humidity sensor first requires determining the measurement range. Except for meteorological and scientific research departments, high temperature and humidity measurement and control generally do not require full humidity range (0-100% RH) measurement.
2) Select measurement accuracy:
Measurement accuracy is an important indicator of temperature and humidity sensors. Every one percentage point increase is a step up, or even a level up, for temperature and humidity sensors. Due to the need to achieve different levels of precision, the manufacturing cost and selling price vary greatly. So users must tailor their products according to their needs and should not blindly pursue "high, refined, and cutting-edge".
If a humidity sensor is used at different temperatures, its reading should also consider the influence of temperature drift. *Relative humidity is a function of temperature, and temperature significantly affects the relative humidity within a space. The temperature changes by 0.1 ℃. A humidity change of 0.5% RH will occur (error). If it is difficult to achieve constant temperature in the usage scenario, it is inappropriate to propose excessively high humidity measurement accuracy.
In most cases, if there are no temperature control measures or the tested space is not sealed, an accuracy of ± 5% RH is sufficient. For local spaces that require constant temperature and humidity control, or for situations where humidity changes need to be tracked and recorded at any time, temperature and humidity sensors with an accuracy of ± 3% RH or higher should be selected.
The requirement for accuracy higher than ± 2% RH may even be difficult for the standard humidity generator used to calibrate the sensor, let alone the sensor itself. It is still difficult to achieve an accuracy of 2% RH for relative temperature and humidity measuring instruments, even at 20-25 ℃. The characteristics given in the product information are usually measured at room temperature (20 ℃± 10 ℃) and in clean gas.
3) Consider time drift and temperature drift:
In practical use, due to the influence of dust, oil, and harmful gases, electronic humidity sensors will age and their accuracy will decrease over time. The annual drift of electronic temperature and humidity sensors is generally around ± 2% or even higher. In general, manufacturers will indicate that the effective usage time for one calibration is 1 or 2 years, and recalibration is required upon expiration.
4) Other precautions
Temperature and humidity sensors are non sealed, and in order to protect measurement accuracy and stability, they should be avoided from use in acidic, alkaline, and organic solvent containing atmospheres as much as possible. Also avoid using in environments with high levels of dust. To accurately reflect the humidity of the space to be measured, sensors should also be avoided from being placed too close to walls or in blind spots where air is not well ventilated. If the room being tested is too large, multiple sensors should be placed.
Some temperature and humidity sensors require high power supply, otherwise it will affect measurement accuracy. Or the sensors may interfere with each other and even fail to work. Suitable and accurate power supply should be provided according to technical requirements during use.
When sensors need to transmit signals over long distances, attention should be paid to signal attenuation.