The antibacterial zone measuring instrument detects the diameter of the antibacterial zone in the culture dish through an optical sensor and a stable light source, and its accuracy depends on the sensitivity of the sensor and the stability of the light source. If the sensor is contaminated or the light source is attenuated, it can cause measurement errors. The following elaborates on the key operational points from two aspects: sensor cleaning and light source maintenance.
1、 Sensor cleaning: ensuring data accuracy
1. Cleaning timing and frequency
Daily maintenance: After the experiment, wipe the sensor surface with a dry and dust-free cloth.
Regular deep cleaning: Use specialized cleaning tools every two weeks to remove stubborn stains.
Clean immediately after contamination: If the sensor comes into contact with splashes, dust, or fingerprints on the culture medium, it should be dealt with immediately.
2. Cleaning tools and materials
Tool selection:
Air blowing: used to remove particulate matter and avoid direct contact with sensors.
Lens paper: Use specialized paper with low fiber shedding and fold it into sharp corners for wiping.
Isopropanol: concentration 70% -90%, used to dissolve organic matter, needs to be dropped on lens paper for use, cannot be sprayed directly.
Prohibited items: regular paper towels, cotton swabs, ammonia containing cleaning agents.
Step by step cleaning process
Power outage and protection: Turn off the instrument power and wear anti-static gloves.
Preliminary dust removal: Use air blowing to spiral blow outwards from the center of the sensor to remove large particles.
Wet cleaning:
Fold the lens paper into 3 layers and drop 1-2 drops of isopropanol.
Wipe in a unidirectional manner from center to edge to avoid back and forth friction.
Replace the lens paper with a clean one and wipe it repeatedly until there is no residue.
Drying treatment: Use dry lens paper to absorb residual liquid and let it air dry naturally for 5 minutes.
Function verification: After booting up, run the self-test program to check the sensor signal strength.
4. Common problem handling
Fingerprint contamination: Use lens paper dipped in a small amount of distilled water to wipe and avoid corrosion of the coating.
Cultivation medium hardening: Place the instrument in a 40 ℃ environment for 10 minutes to soften the hardening before cleaning.
Scratch repair: If there are small scratches on the surface of the sensor, contact the manufacturer for replacement.
2、 Light source maintenance: maintain long-term stability
1. Light source type and lifespan management
LED light source: lifespan>20000 hours, but light intensity attenuation needs to be monitored.
Halogen lamp: with a lifespan of about 2000 hours, it needs to be replaced regularly.
Replacement standard: Replace when the brightness of the light source drops to 80% of the initial value.
2. Daily usage standards
Avoid frequent switching: The lifespan of LED light sources is reduced by about 1 hour each time they are switched on and off. It is recommended to use them continuously for more than 30 minutes.
Control environmental temperature: The temperature around the light source should be less than 40 ℃ to avoid accelerated aging due to high temperatures.
Voltage stability: Use a regulated power supply to prevent voltage fluctuations from damaging the light source.
3. Cleaning and maintenance process
Surface cleaning of light source:
Blow off the dust inside the lampshade with air.
If the lampshade is heavily contaminated, wipe it with lens paper dipped in isopropanol.
Mirror adjustment:
Check the angle of the reflector every quarter to ensure that the light is perpendicular to the sensor.
If the reflector shifts, contact the manufacturer for adjustment.
Maintenance of cooling system:
Clean the dust from the cooling fan and ensure that the air duct is unobstructed.
Check if the heat dissipation silicone grease is dry.
4. Fault warning and handling
Insufficient light intensity:
Phenomenon: The edge of the antibacterial zone is blurred, and the measured value fluctuates by more than 0.5mm.
Solution: Replace the light source or adjust the current.
Light source flickering:
Reason: Poor power supply contact or aging filament.
Solution: Check the power cord connection and replace the light source.
Color temperature offset:
Phenomenon: The image appears yellowish or bluish, which affects the recognition of the edge of the antibacterial zone.
Processing: Calibrate the color temperature of the light source.
3、 Comprehensive maintenance recommendations
Establish maintenance records: record the replacement time of the light source, the number of sensor cleaning times, and any abnormal situations for easy traceability of issues.
Regular calibration: Conduct a full system calibration once every quarter.
Environmental control: Maintain laboratory humidity of 40% -60% and temperature of 20 ℃ -25 ℃ to reduce static electricity and condensation risks.
Operation training: Ensure that laboratory personnel master the correct power on/off sequence and avoid accidental contact with sensors.
Summary: Sensor cleaning should follow the principles of "dust-free, non-destructive, and unidirectional wiping", while light source maintenance should focus on lifespan monitoring, heat dissipation management, and light intensity calibration. By standardizing operation and regular maintenance, the service life of the antibacterial zone tester can be significantly extended, ensuring the repeatability and accuracy of measurement results.