The testing platform adopts PLC control and adjusts the air pressure from 0-20Kpa through a pressure fine-tuning valve to simulate the high and low water level slots inside the washing machine when water enters. The pressure difference generated is used to test the on/off contacts of the water level sensor. Each workstation can be connected to the water level sensor through a hose connection. Suitable for three pin electromagnetic water level sensors and two pin mechanical sensors. Set different output pressure values to conduct low-pressure and high-pressure tests on the water level sensor. By setting the test frequency and on-off cycle, the service life of the water level sensor in long-term pressure testing can be judged to determine whether it meets the design and usage standards.

Washing machine water level sensor life testing machine

Basic testing conditions

-Test object: Electromagnetic and mechanical (2-pin/3-pin) water level sensors

-Air pressure simulation: adjustable air pressure from 0 to 20kPa, simulating the pressure difference between high and low water levels in a washing machine

-Action frequency: 20 times/minute

-Total number of cycles: 30000~50000 times

-Power supply conditions: rated voltage (DC5V/AC220V), compatible with sensor specifications

-Environmental requirements: normal temperature and pressure (25 ℃± 5 ℃); Scalable high and low temperature (-20 ℃~70 ℃), humid and hot (40 ℃/90% RH) environmental testing

test project

1. On/off life test

Simulate water level rise and fall triggering sensor contact NO/OFF repeatedly to detect contact fatigue, poor contact, and failure.

2. Stability of Action Pressure

Before and after the durability test, measure the change in high/low water level action pressure.

3. Electrical performance verification

-Insulation resistance: Terminal to shell ≥ 10M Ω

-Signal response: Real time collection of on-off signal IO to determine action consistency

4. Environmental adaptability and durability

-Heat/Cold Resistance: After a constant temperature of 70 ℃/-20 ℃ for 168 hours, the water level deviation is ≤ 15mm

-Heat and humidity resistance: 168h in 40 ℃/95% RH environment, with no performance degradation

-Temperature cycle: high temperature → room temperature → low temperature cycle 20 times, without cracking or parameter drift

Judgment criteria (GB/T 24986.3-2024 Reliability requirements for washing machines)

-After the experiment, the sensor showed no air leakage, membrane damage, or contact erosion

-Action water level deviation ≤± 15mmH ₂ O

-Electrical parameters (resistance/capacitance) comply with factory specifications