What are the requirements of constant temperature and humidity test chamber for measuring instruments?

　　Constant temperature and humidity test chambers are also called constant temperature and humidity test machines, which are widely used in material testing in the instrumentation, electronics, food and other industries. However, to test whether a constant temperature and humidity test chamber is qualified, measuring instruments are needed. So what measuring instruments are needed to test constant temperature and humidity test chambers? What are the requirements for measuring instruments?

　　What are the requirements for measuring instruments in constant temperature and humidity test chambers? Please carefully read the requirements for measuring instruments in the GBT 5170.5-2008 standard.

　　Temperature measuring instruments

　　1. The temperature measurement system composed of platinum resistance, thermocouple sensor and secondary instrument shall have an expanded uncertainty (k=2) of the measurement result not greater than 1/3 of the allowable deviation of the tested temperature.

　　2. Platinum resistance sensors should comply with Class A of IEC60751, and platinum resistance sensors should comply with GB/T16839.1.

　　3. The 50% response time of the sensor in the air should be between 10s and 40s, and the response time of the temperature measurement system of the constant temperature and humidity test chamber should be less than 40s.

　　Wind speed measuring instrument

　　Use various network speed meters, the induction value is no more than 0.05m/s.

　　Noise measurement instruments

　　The expanded uncertainty (k=2) of the measurement result of the A-weighted network sound level meter is no more than 1dB.

　　Note: The climate conditions, power supply conditions, water conditions and other conditions of the constant temperature and humidity test chamber during inspection shall comply with the provisions of Chapter 4 of GB/T5170.1-2008. The appearance and safety requirements shall comply with the provisions of Chapter 8 of GB/T5170.1-2008.