As the core equipment for environmental monitoring, the stability and accuracy of temperature and humidity transmitters directly affect the reliability of data. Daily maintenance and sensor protection need to start from four aspects: environmental management, cleaning and maintenance, operating standards, and long-term storage. The following are specific practical methods.
1、 Environmental adaptability management
Temperature and Humidity Control
Avoid long-term exposure of the transmitter to the environment (such as temperature>85 ℃, humidity>95% RH or<5% RH) to prevent sensor performance degradation. For example, when installing in a chemical workshop, it is necessary to stay away from high-temperature sources such as reaction vessels and install moisture-proof covers to ensure that the environmental temperature and humidity are within the range of 20% -80% of the equipment range.
Dust and corrosion prevention
In environments with dust or corrosive gases such as chlorine and ammonia, it is necessary to regularly check the integrity of the sensor protective cover. A certain electronics factory discovered that the humidity sensor had a slow response due to dust blockage. After replacing the protective cover with a dust proof rating of IP65, the measurement accuracy was restored.
Mechanical protection
Avoid vibration or impact on the transmitter, especially for capacitive humidity sensors, whose sensitive components are prone to damage due to mechanical stress. During transportation or installation, shock-absorbing pads should be used to secure the equipment and ensure smooth contact between the probe and the measured medium.
2、 Regular cleaning and calibration
Sensor cleaning
Dry cleaning: Use a soft bristled brush or compressed air to remove dust from the surface of the probe, avoiding scratching with sharp tools.
Wet cleaning: If the sensor is contaminated with oil or condensed water, a dust-free cloth dipped in isopropanol or deionized water can be gently wiped, dried, and reinstalled. A certain food warehouse discovered that the temperature sensor was short circuited due to condensed water, and regular cleaning was carried out to avoid abnormal data.
Function self check
Check the stability of the output signal through the transmitter display interface or upper computer software every month. If data fluctuations are found to be greater than ± 2% RH or ± 0.5 ℃, environmental interference or sensor aging issues should be immediately investigated.
periodic calibration
It is recommended to calibrate once every quarter for industrial scenarios, and shorten the frequency to monthly for harsh environments such as high salt spray and high humidity. Preheat the equipment for 30 minutes before calibration to ensure that the sensor reaches thermal equilibrium.
3、 Operating standards and storage management
Installation specifications
The temperature sensor probe should be inserted into the measured medium at a depth of ≥ 1/3 of the diameter to avoid being close to walls or corners that may cause poor airflow.
The humidity sensor probe should be installed vertically to prevent condensed water from flowing into the interior of the equipment along the probe.
Power off operation
When replacing sensors or repairing equipment, the power should be cut off first to prevent static electricity or accidental operation from damaging the circuit board. A certain laboratory experienced module burnout due to live plugging and unplugging of sensors. After strictly following the power-off process, similar malfunctions did not occur again.
Long term storage conditions
If the equipment needs to be idle for a long time, it should be cleaned and sealed in a dry environment (humidity<60% RH), and regularly powered on (once every 3 months) to activate the sensor and prevent component aging.
4、 Sensor protection upgrade plan
Install protective casing
In high temperature or corrosive environments, stainless steel or polytetrafluoroethylene sleeves can be added to sensors to extend their service life. For example, a steel plant installed temperature sensors in high-temperature flue gas ducts using ceramic sleeves that can withstand temperatures up to 1200 ℃, which extended the equipment's lifespan from 3 months to 2 years.
Redundant design
Two transmitters can be installed in parallel at key monitoring points, and when the main equipment fails, it will automatically switch to the backup equipment to ensure data continuity. A certain data center uses redundant design to avoid interruptions in temperature and humidity monitoring caused by single point failures.
Through systematic daily maintenance and sensor protection measures, the reliability and service life of temperature and humidity transmitters can be significantly improved, providing stable data support for industrial control, environmental monitoring, and other fields.