Usually we can produce a negative pressure of the small volume pumps are called miniature vacuum pump, but the product selection must be strictly distinguished. The true sense of the miniature vacuum pump (such as VM series, VAA series, PK series, PC series, VCA series, VCC series, VCH series, PH series, FM series, FAA series, PCF series) Vacuum pump, it can drive a larger load. The gas sampling pump (such as the PM series) working pressure pump inside and outside the smaller, so it with a small load. It is because of different requirements on the load capacity, resulting in micro-vacuum pump and gas sampling pump parts are very different. Miniature vacuum pumps have high demands on the diaphragm and the motor. For the two main parts, the fatigue strength, reliability, life expectancy and other technical indicators are required to meet the conditions of the load, unlike the gas sampling pump only required at very light load standards (test proved that the load is slightly larger Gas sampling pump is easy to damage). Therefore, the cost of the two micropumps is quite different. In summary, if the miniature vacuum pump for gas sampling, is bound to get high reliability, but the price is high; if the gas sampling pump slightly larger load situation, the reliability, life is greatly reduced, or even impossible Works fine, though it has an advantage in price. Selection is best to consult the technical department clearly, so as to take into account cost and performance. Some gas sampling pumps can also achieve better vacuum and flow indicators, however, to reach this technical indicator and can work reliably under this indicator for a long time are two different things. For example, a miniature pump can reach a vacuum of 30KPa, then when the pump's suction port is often at this level of vacuum, the pump can work reliably? Therefore, the pump to achieve the target and it can work reliably indicators are not the same, please confirm to the dealer to confirm.