Large data centers, IDC computer rooms, power distribution cabinets and other places that have higher requirements for data security, but the monitoring of temperature and humidity in the computer room space can no longer meet the requirements of fine management. In practical applications, it is often found that the temperature and humidity at each point in the computer room are normal, but the normal operating environment of the equipment inside the cabinet cannot be guaranteed. The problem of heat dissipation of equipment inside the cabinet leads to the widespread phenomenon of local hot spots in the cabinet, which has become one of the root causes of equipment failure. There is an urgent need to monitor the temperature and humidity of the machine room cabinet.

At present, many computer room managers use 24-hour special personnel on duty to inspect the environmental equipment of the computer room regularly, which not only increases the burden on the management personnel, but also more often, they cannot eliminate the fault in time, and there is no scientific management of the time and responsibility of the accident. Therefore, it is necessary to monitor the temperature and humidity of the computer room and the video surveillance between the server channel.

For a larger computer room, due to the influence of airflow and equipment distribution, the temperature and humidity values will be quite different. The number of additional temperature and humidity sensors should be determined according to the actual area of the main computer room and the actual placement of the server to detect the temperature and humidity in the computer room. Through the linkage between the sensor and the industrial control computer in the main monitoring room, the real-time display of the temperature and humidity of the computer room on the same screen can be realized. When the temperature and humidity of the computer room exceed the predetermined value, the system will send out an alarm sound to remind the on-site management personnel. In addition, for future expansion needs, a wireless cat communication interface can be reserved in the software and a wireless cat card slot can be reserved on the hardware to facilitate the short message alarm function in the future.

This paper recommend selects a unique process design, low price, high precision, digital output temperature and humidity sensor-HTU21D. Better to achieve the measurement of air humidity. and displayed.

Digital output temperature and humidity sensor module HTU21D Product introduction:

Based on FranceHumirelMade of the company's high-performance humidity sensing components, the new generation of HTU21D temperature and humidity sensors have established new standards in terms of size and intelligence: it is embedded in a double-row flat leadless DFN package suitable for reflow soldering, with a bottom surface of 3x 3mm and a height of 1.1mm. The sensor outputs a calibrated digital signal in standard I2C format. Diversified output mode, wide working voltage range, and high temperature accuracy and humidity accuracy. HTU21 series modules are designed for low power consumption and small volume applications. They have the advantages of good quality, fast response speed, strong anti-interference ability, high cost performance, small volume (3x 3mm), and extremely low power consumption.

Digital output temperature and humidity sensor module HTU21D sensor important parameters:

Supply voltage: 1.5V-3.6V

Humidity measurement range: 0-100% RH

Temperature measurement range: -40 ℃-125 ℃

Max power consumption: 2.7uW

Communication mode: I2C

Humidity accuracy range (10% RH to 95% RH): HTU21D ± 2% RH

Humidity hysteresis: ± 1% RH

Measurement time: 50ms

Annual drift:-0.5%RH/year

Response time: 5 s