实验动物 z-bo 2020-07-29 723

　　(1) Measurement conditions

　　Laboratory animal facilities will operate continuously for at least 48 hours near the load.

　　(two) measuring instrument

　　1. The instrument is a 0.01 or higher thermal bulb electric anemometer, an intelligent digital display anemometer or a vent hood, and it needs to be tested after calibration.

　　2, the measuring equipment must be within a valid inspection period.

　　(3) Measuring method

　　1. Measure the air volume at the air outlet (positive pressure) or the air volume at the air outlet (negative pressure) and the volume of the room, and calculate the number of air changes.

　　2. If the tuyere is circular, if the diameter is less than 200 mm, select two measuring points in the radial direction; if the diameter is 200-300 mm, use concentric circles to create two rings of equal area. Select four measurement points upwards. Measurement: For diameters from 300 mm to 600 mm, use concentric circles to create three belts of equal area, and select six measurement points in the radial direction for measurement. If the diameter exceeds 600 mm, create 5 concentric circles and measure 10 points to obtain the wind speed. average value.

　　3. If the tuyere is square or rectangular, divide the tuyere compartment into multiple equal areas less than 100mm x 150mm, measure the wind speed at the center of each equal area, and obtain the average value as the average wind speed. I will.

　　4. For circular outlets, auxiliary outlet pipes or fan-shaped outlet pipes with the same pipe diameter and length of 1000 mm can be used, and the measurement shall be carried out according to the method described in "2". For square or rectangular, please use the auxiliary duct of corresponding shape and cross section, and collect samples for measurement according to the method described in "3".

　　5. When using a gas hood for measurement, please fix the gas hood directly on the exhaust port for measurement.

　　(4) Calculation formula

　　Formula (1) is used to calculate the ventilation rate.

　　Q = 3600Sv-(1)

　　among them:

　　Q is the required air exchange rate, in cubic meters per hour (m3/h),

　　S is the effective area of the export, the unit is square meter (square meter). M);

　　V-average wind speed, m/s (m/s).

　　The standard ventilation rate is obtained by multiplying the ventilation rate by the correction factor. The correction coefficient is 1.0 at the intake port and 0.8 at the exhaust port. When converted to formula (2) at 20°C in the standard state,

　　Q = 3600 [(273 + 20)/(273 + t)Sv-(2)

　　among them

　　Q is the air exchange rate in cubic meters per hour (m3/h) under standard conditions,

　　T is the supply air temperature in degrees Celsius (°C),

　　V-the average wind speed in meters per second (multiple sclerosis).

　　The amount of air exchange can be obtained from equation (3):

　　= Q0/V(3)

　　among them:

　　The time unit of air exchange per hour (times/hour) Q0 is the air supply per hour, in cubic meters (m3/h), and V is the indoor air volume, in cubic meters (m3).