There are many common errors in sensor installation work, all of which can lead to measurement errors. Inaccurate measurement results may lead to energy waste, low product quality and 

process efficiency, products that do not meet requirements (resulting in recalls and high economic losses), and poor environmental conditions for personnel inside the building. The following 

tips will help you complete the correct installation of sensors in one step, thereby improving the accuracy of measurements.

When installing indoor wall mounted sensors, always:

1. Choose the correct installation location

The selection of installation location is crucial when installing measurement sensors for controlling specific spaces. In order for the measurement results to accurately reflect the actual 

feelings of indoor personnel, you need to choose an installation location that can represent the indoor environment. This type of location should have good ventilation and no heat sources 

nearby.

Some common mistakes to avoid:

Install sensors in areas with poor air circulation, such as behind doors, equipment, or furniture.

Install sensors near objects that can generate heat, such as radiators, heating pipes, printers, or copiers.

Install the sensor in a location where sunlight can directly reach it (taking into account the sunlight exposure at any time of the day).

Install wall mounted sensors on the ceiling.

Install sensors tightly against the ventilation duct (this will cause the sensor readings to change before the space reaches a new equilibrium state. This means that the system needs 

to be adjusted more frequently.)

2. Ensure that the sensor is installed in the correct direction

Wall mounted sensors integrate sensors and electronic components into a small box, so specific directions need to be followed during installation. The heat generated by electronic devices 

will flow upwards, so you need to place the sensor below the electronic device to avoid heat affecting the measurement results. In addition, if you install the side of the sensor on the wall, the 

hot air inside the sensor will not be able to be discharged, resulting in temperature readings higher than the actual value and humidity readings lower than the actual value.

3. Install multiple sensors side by side

Some wall mounted sensors generate heat, so it is not recommended to install one wall mounted temperature or humidity sensor above another. If you do this, the heat generated by 

the sensor may affect the measurement results of another sensor. Gas sensors generate more heat than other sensors, making this issue particularly serious. It is best for you to follow 

the manufacturer's installation recommendations and choose to install sensors side by side. If it is necessary to install sensors vertically, the sensor that generates more heat should be 

installed above other sensors.

4. Consider indoor ventilation conditions

The design purpose of standard humidity and temperature sensors is for typical office environments. If the sensor is installed in a room with downward exhaust (such as a clean room), 

the heat from the top of the electronic components will be carried by the airflow to the sensor below, resulting in an increase in the measured temperature. The solution to this problem 

is to use sensors specifically designed for cleanrooms or similar spaces. The sensors and electronic components in this type of sensor are separated from each other to ensure that the 

sensor is not affected by heat (while maintaining sufficient contact with the environment).

5. Pay attention to whether there is a pressure difference or poor sealing

If there is a pressure difference between the room measured by the sensor and the cavity of the building wall, the readings measured by the sensor may be inaccurate. If the air pressure 

in the room is low, cold air will flow directly into the sensor through the cable holes on the wall, causing a significant decrease in temperature readings. The solution to this problem is to 

seal the hole formed by the cable passing through the wall.

6. Avoid errors caused by thermal conduction

Reinforced concrete walls can conduct heat, so sensors fixed to the wall with bolts may not accurately indicate air temperature and humidity. The solution to this problem is to add a layer 

of insulation material between the wall and the transmitter, or install the sensor on the inner wall or a surface with better insulation.

Concrete can also affect the measurement results of carbon dioxide. If a carbon dioxide sensor is installed on a concrete surface, the measured carbon dioxide reading will be extremely low, 

but this cannot accurately reflect the concentration of carbon dioxide in indoor air. Generally speaking, placing a board under the sensor can solve this problem.

7. Avoid errors caused by body temperature

The error of inaccurate readings caused by body temperature usually exists in handheld measurements. If you need to perform handheld measurements, please do not place the measuring 

device too close to your body and do not breathe into the sensor.

When installing pipeline mounted sensors, always:

Part 1: Ensure consistent temperature inside and outside

For pipeline installed equipment, a common cause of error is the temperature difference between the internal and external air of the pipeline (for example, installing the equipment inside 

the intake pipeline to measure outdoor conditions). If there is a temperature difference, heat will flow from the high temperature side to the low temperature side through the pipeline sensor 

pipeline, resulting in temperature and humidity readings deviating from the actual values.

If the insulation of the pipeline is good, the internal air flow rate is low, and the sensor insertion degree is shallow, the impact in this regard will be more significant. There are two 

solutions: first, use high-quality outdoor sensors; 2、 Properly insulate the sensor.

2. Prevent damage caused by condensation

If the humidity inside the pipeline is high and the outdoor temperature is low, the sensor pipeline will become cooled due to thermal conduction effect, resulting in the formation of 

condensed water on the sensor. Condensation water will also form on the inside of the pipeline and flow along the pipeline to the sensor. If the sensor tilts downwards, it will not only 

result in inaccurate readings, but may even cause corrosion. To minimize the impact (and potential damage) caused by condensation, the sensor should be kept level (and slightly tilted 

upwards if necessary). This can keep the condensed water away from the sensing element, ensuring safety.

3. Avoid installing sensors in blind spots

Just like when installing indoor wall mounted sensors, you need to install the sensors in representative locations. If you install the sensor in a dead corner of the pipeline, air will not flow 

through the sensor, which means that the measurement results will not represent the situation of the main airflow. If the air around the sensor stagnates, the changes in this part of the 

airflow will be slower than the main airflow, and the readings will not be able to accurately reflect the current situation at all times. Therefore, you need to avoid installing the sensor in blind 

spots and ensure that the sensor always maintains proper contact with the airflow.

4. When installing a part of the sensor inside the process, please choose carefully

When installing sensors for certain process flows, it is necessary to insert some parts of the sensor into the interior and leave some parts outside, and the temperature difference between 

the interior and exterior may be very large. For example, when measuring the temperature and relative humidity inside a baking furnace through an insulated wall, a sensor made of metal 

material will have a temperature reading lower than the actual value inside the furnace due to thermal leakage, while the relative humidity reading will be higher than the actual value inside 

the furnace. The speed of heat leakage is related to the air flow rate, and the probe cools faster in still air, resulting in greater errors. If the humidity is high, not only will the measurement 

results of temperature and relative humidity be inaccurate, but condensation problems may also occur.

There are two solutions to this problem. 1、 Improved installation: Insert the probe deeper and/or insulate the part of the probe left outside. This can minimize the temperature difference 

between inside and outside as much as possible and help you accurately measure relative humidity. You can also consider whether to measure relative humidity. You can consider using other 

parameters, some of which have the advantage of not being affected by temperature. This way, you can use a heating probe to fundamentally avoid the formation of condensation water.

5. Avoid installing sensors too close to humidifiers

The pipeline humidity sensor is usually used for humidity control, which is finally realized by atomizer or spray humidifier. If the installation position of the pipeline sensor is too close to the 

humidifier, it will cause moisture to accumulate on the sensor and form condensation, resulting in the sensor being unable to make accurate measurements.

When the situation is severe, the sensor will be damaged. Even if the situation is not as severe, if the sensor continues to come into contact with moisture, its measurement results will not 

be able to be used for precise control. The sensor drying and rewetting, wet and redrying will cause severe fluctuations in humidity readings, resulting in continuous operation of the equipment 

and difficulty in accurately maintaining various conditions. In addition, it can also lead to sensor drift and contamination in advance, further expanding the error.

To avoid these issues, the installation position of the pipeline sensor should be kept at a sufficient distance from the humidifier. The specific distance depends on the size of the pipeline and the 

air flow rate, but it is usually recommended to be 5 meters apart. In addition, you can also reserve an additional access port downstream of the pipeline sensor when installing it. This access 

port can be used for temporary installation of reference probes in the future to verify and calibrate the measurement results of the main sensor. When not in use, the access port can be sealed 

with duct tape to prevent leakage.

When installing outdoor sensors, always:

1. Use a radiation shield

Solar radiation can cause the temperature of the sensor to rise by 2 ° C. To avoid the influence of solar radiation, the sensors used should be equipped with high-quality radiation shields 

(the bottom of the shield should be black). Wind can reduce heat, so please install the sensor in a well ventilated location. In addition, the temperature of the radiation protection cover will 

increase faster after it becomes dirty, so please keep the protective cover clean. Protective covers installed in urban areas may require more frequent cleaning. If the outer side of the protective 

cover turns black or dirty, it means that it needs to be cleaned immediately. If you plan to install the sensor on a wall, you should usually choose a north facing wall that is less exposed to sunlight.

2. Protect sensors from the effects of rain and harsh weather

Rain, snow, and condensation can form water accumulation on or near the surface of the sensor, causing sensor readings to drift and humidity readings to be higher than actual values. Adverse 

weather conditions may also damage sensors. You can take the following measures to protect sensors from weather conditions:

Use sensors designed specifically for working in humid outdoor conditions

Install the sensor in a well ventilated location (wind can promote moisture evaporation, ensuring accurate and reliable measurement results)

For industrial applications, a heating probe can be used to avoid the influence of condensate

3. Ensure that the installation position of the sensor is away from other heat sources

The walls of buildings, due to their large mass, can store a large amount of heat or cold. In addition, it can also become hot due to solar radiation. If the installation location of the sensor is 

too close to the wall or black roof without leaving enough space, the measurement results may be inaccurate.

In order to reduce the impact of wall heat, outdoor measurement sensors should be installed in well ventilated locations. It is best to install it on a pole away from the building or above the 

roof. Do not install it on dark surfaces that are directly exposed to sunlight, and do not install it under eaves. Hot air will accumulate under the eaves, resulting in inaccurate and unreliable 

measurement results.