『cfm meter for hvac|mass flowmeter』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)
1. How to calculate the heating power required for a certain area to reach a certain temperature
power * time=specific heat capacity * mass * temperature difference; That is, Pt=cm Δ t; Where m=ρ V. Assuming specific heat capacity c J/(kg Kelvin); Kelvin=K=absolute temperature. Assuming density=r (kg/M ^ 3, kg/cubic meter); Volume=A (M ^ 3, cubic meters); Mass=density * volume=rA; temperature difference=DT (℃); Time=t (sec); Effective utilization rate~90%; Heating power * effective utilization rate=(rA) * c * DT/t (J/sec). Additional information: Heat Q=I ² Rt=Pt; I current, R resistance, t heating time. Power P=UI=U ²/R=I ² R; U voltage, I current, R resistance. Thermal equilibrium Q=Pt=mc (T2-T1); P power, t time, m mass, c specific heat capacity, T2 final temperature, T1 initial temperature. Temperature rise T2-T1=Pt/ml. Heating time t=mc (T2-T1)/P. When there is no phase change (such as heating air), if there is a phase change (such as heating water and changing from liquid to gas), the latent heat of phase change cannot be ignored and needs to be calculated in segments. The total heating time t=t liquid+t evaporation+t gas, that is: t liquid=mc liquid (100-T1)/P, t evaporation=m/V evaporation, t gas=mc gas (T2-100)/P. In the formula, the time required for liquid t to boil (water is 100), m mass, specific heat capacity of liquid c, boiling temperature at 100, initial temperature at T1, and P power; The evaporation amount or rate per unit time during V evaporation and vaporization, the specific heat capacity of the gas phase, and the T2 termination temperature. Reference source: Baidu Baike - Heating
2. Unit of air volume
The unit of air volume is usually cubic meters per minute or cubic feet
3. Characteristics of dust particle counter
Date and time display;
; USB high-speed communication interface; RJ-45 remote control communication interface; Built in COM serial printer interface; Count over limit alarm: The instrument can set six levels of count over limit alarms (corresponding to ISO levels 4 to 9): level 1, level 10, level 100, level 1000, level 10000, level 100000, and level 1000000; Compliant with ISO14644-1/GB50073-2001 (CLASS4, 5, 6, 7, 8, 9) 2010 version GMP (measurement of static and dynamic states at four levels A, B, C, and D), FS-209E (level 10, 100, 1000, 10000, 100000, 300000, 1000000) and other levels of testing, compliant with JJF-1190-2008 dust particle counter measurement calibration specifications and JIS B9921:1997 with ≤ 1 data storage per
Hot Blog
Related AD
