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Aosong Electronic Temperature and Humidity
Sensor Design Guide
——Use temperature and humidity sensors correctly
Preface
Aosong electronic temperature and humidity sensor (hereinafter referred to
as the sensor) is a temperature and humidity composite sensor with calibrated
digital/analog signal output, and applies dedicated digital module acquisition
technology and temperature and humidity sensor technology to ensure that the
product has extremely high reliability and excellent long-term stability. In order
to make full use of its excellent performance and features, this document
makes provisions for the design of some housings, PCBs, software, etc. and
provides assistance in the design stage.
Please note that unreasonable design of housing, PCB, etc. may cause
significant temperature and humidity deviation and increase in response time,
so please design strictly in accordance with the requirements of this document.
The most important design advice on accuracy
The accuracy of measurement depends not only on the accuracy of the sensor itself,
but also on the design of the sensing system. The sensor collects the temperature and
humidity from its direct environment, so the relativity between the local condition of the
sensor and the measured condition is very important. Figures 1 to 4 illustrate the most
important design recommendations to ensure good sensor performance: contact
environment, air-tightness to the air inside the housing, small dead space volume, and
isolation from heat sources. The following pages contain a more in-depth introduction.
1. The sensor is in good contact with the environment
Figure 1: The opening of the shell should have a good channel in contact with the environment, so that the sensor can exchange well with
the outside air.
2. The sensor is completely isolated from the dead space inside the housing
Aosong Electronic Temperature and Humidity Sensor Design Guide
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Figure 2: The sensor is completely isolated from the dead zone air inside the housing, which minimizes the influence of the airtight air
inside the housing on the sensor
2. The closed dead zone around the sensor is small in size
Figure 3: The small dead volume enables the sensor to quickly adapt to changes in the environment.
3. The sensor is isolated from the heat source
Figure 4: The isolation of the sensor from the heat source in the PCB reduces the influence of internal heating on the sensor.
Precision introduction
When using the Aosong electronic sensor for measurement, the temperature and
relative humidity deviation between the sensor and the environment must be avoided.
Usually the root cause of temperature deviation is the heat source, while humidity deviation
is mainly caused by temperature deviation and slow response time. Please note that due to
the dependence of humidity on temperature, every temperature deviation will cause a
humidity deviation-relative humidity, a deviation of 1°C at 90%RH will result in a humidity
deviation of 5%RH.