Midmark M9® -05x / M11® -05x Sterilizer Water Level Sensor Test and Repair

WARNING

To prevent risk of shock always disconnect power before removing covers or performing any service procedure.

 

Model

 M9 -050, -053 M11 -050, -051, -053
Serial Number All All
WARNING

Some procedures require power to be connected with covers removed. Line voltage is present. Use extreme caution to prevent electric shock.

M9/M11 Steam Sterilizer Water Level Sensor Testing

Voltage Test

1.Set meter to VDC.

2.Place meter probes on points TP177 and TP292 (as shown in the figure above).

3.Activate the water level sensor by filling chamber with water up to the sensor and check reading.
LED D52 should light up.

Meter Reading

Required Action

No water touching sensor = approximately 3.3 VDC Water touching sensor (chamber full) = approximately 0 VDC

PC board is OK . Perform Continuity Test.

Any other reading

Replace PC board.
WARNING

Sterilizer or components may be hot or become hot. Wait until the sterilizer or components are cool to the touch before continuing service.

M9/M11 Steam Sterilizer Water Level Sensor Testing

Ensure that the sensor is dry. Any water on the sensor could cause inaccurate readings.

Resistance Test

1.Empty any water from chamber and dry sensor.

2.Disconnect wire from sensor terminal.

3.Set meter to Ohms (Ω).

4.Place one meter probe on sensor terminal and the other probe on the chamber wall (as shown in the figure above).

Equipment Alert

Residue buildup on the sensor disk can cause malfunctions during the Filling mode. Clean the sensor disk with Speed-Clean and an abrasive pad; then dry disk thoroughly.

Meter Reading

Required Action

OL

Water level sensor is good.

Any reading other than OL

Replace water level sensor.