According to the different working principle, generally divided into two types: vacuum type and gravity type.

The vacuum toilet is generally classified into vacuum holding type, vacuum intermittent type, vacuum push-pull type, and vacuum online type.

1  Withstand voltage fluctuation ability - GB/T 25119
2  Insulation resistance and dielectric strength - GB/T 12817
3  Electromagnetic compatibility - GB/T 24338.4
4  Protection level - GB 4208
5  Noise and odor
5.1    Noise
 Noise meets the requirements of different level of vehicles.
 If not specified, the following table requirements must be met, and there must be no weird squeaks:

5.2     Odor
 There should be measures to prevent sewage from entering the car.
 The gas discharged from the vacuum system should be filtered.
6       Reliability
 The average time between failures is not less than 1×10⁴ h or the number of operations is not less than 3×10⁵ times, whichever comes first.
7       Maintainability
  Ensure the maintenance space of the components, especially the underside of the squatting pan and the accessories on the sewage tank
  There should be corresponding maintenance instructions and cycle plans.
8       Security
 The power source, water source and compressed air source should be safe under all conditions.
 Non-metallic materials and wires and cables comply with TB/T 3138 (DIN 5510-2)
 The load carrying capacity of the dirt box complies with UIC 566 or EN 12663
 If can directly see or touch the drain valve, need to add a warning sign to prevent the person from entering the injury.