1、 Daily cleaning and appearance inspection

1. Clean the surface of the sensor
   • Tool selectionUse clean, soft dust-free cloth or specialized lens paper, avoid using rough fabrics or tissues, and prevent scratching the sensor surface.
   • DetergentIf there is oil or stubborn stains on the surface of the sensor, it can be wiped with a small amount of isopropanol (IPA) or specialized electronic cleaner. It is strictly prohibited to use corrosive solvents such as alcohol and gasoline.
   • frequencyClean once a week or month according to the usage environment (such as dust and oil pollution), and increase the frequency in humid or corrosive environments.
2. Check the casing and connectors
   • Confirm that the sensor housing has no cracks, deformations, or looseness, and whether the protection level (such as IP67) meets environmental requirements.
   • Check if the cable connection is secure, if the plug is not oxidized or loose, to avoid poor contact and signal abnormalities.

2、 Regular calibration and performance testing

1. calibration cycle
   • routine operating conditionsCalibrate every 6-12 months.
   • harsh environmentWhen it comes to high temperature, high humidity, strong vibration, or frequent replacement of the testing object, it is recommended to calibrate it every 3 months.
2. calibration method
   • Shooting sensorAdjust the alignment accuracy between the transmitter and receiver, and test the response distance and sensitivity using standard detection materials (such as metal sheets of specified size).
   • Reflective plate sensorClean the surface of the reflector to ensure there are no scratches or stains, and adjust the distance between the sensor and the reflector to the rated value.
   • Background suppression sensorVerify the background suppression function using different colors or materials of the test substance to avoid false positives.
3. performance testing
   • Monitor sensor output signals (such as NPN/PNP, voltage/current) through PLC or dedicated tester to confirm signal stability and no jitter.
   • Test whether the response time meets the specifications (such as ≤ 1ms), and exceeding the time limit may indicate internal circuit aging.

3、 Environmental adaptability maintenance

1. temperature control
   • The working temperature range of sensors is usually -25 ℃~+70 ℃. Exceeding this range may result in decreased sensitivity or damage.
   • In high-temperature environments, ensure that there is sufficient heat dissipation space around the sensor and avoid direct sunlight or proximity to heat sources.
   • In low-temperature environments, preheat the equipment to room temperature before starting the sensor to prevent condensation from freezing.
2. Moisture and dust prevention
   • In humid environments, regularly check whether the sensor sealing ring is aging, replace it if necessary, and apply silicone grease to enhance sealing.
   • When there is a lot of dust, install a dust cover or choose a sensor with a higher protection level (such as IP69K), and shorten the cleaning cycle.
3. Anti vibration and anti impact
   • When installing sensors, use shock-absorbing pads or fixed brackets to prevent internal components from loosening due to equipment vibration.
   • It is strictly prohibited to strike the sensor housing with hard objects to prevent internal optical path deviation or circuit board breakage.

4、 Electrical Connection and Power Management

1. Power Stability
   • Ensure that the power supply voltage is within the rated range of the sensor (such as 24VDC ± 10%), as excessive voltage fluctuations may damage internal components.
   • Use a regulated power supply or UPS to avoid voltage surges caused by frequent power on/off.
2. Wiring specifications
   • When the cable length exceeds 5 meters, shielded cables should be selected and grounded at one end to prevent electromagnetic interference (EMI) from affecting signal stability.
   • Avoid parallel wiring of sensor cables and power cables, and use metal conduits for isolation if necessary.
3. overload protection
   • Install fuses or current limiting resistors at the output end to prevent short circuits or overload damage to the sensor.
   • Regularly check whether the fuse is blown and replace it with the same specification and model in a timely manner.

5、 Fault diagnosis and emergency response

1. Common faults and their solutions

   Fault phenomenon	Possible reasons	solution
   The indicator light is not on.	Power not connected, fuse blown	Check the power circuit and replace the fuse
   Unstable output signal	Uneven reflection on the surface of the test object and interference from ambient light	Adjust the sensor position and install a light shield
   Misdetection or missed detection	Alignment deviation and improper sensitivity setting	Re calibrate and adjust the sensitivity potentiometer
   Response time becomes longer	Internal dust accumulation and light path pollution	Clean the surface of the sensor and check if the light path is unobstructed

2. emergency measures

   • If the sensor suddenly fails, immediately switch to the backup sensor (if any) to avoid production line shutdown.
   • Record the environmental conditions at the time of the malfunction (such as temperature, humidity, and the status of the detected substance) for subsequent analysis.