1、 Daily cleaning and maintenance

1. Cleaning of optical components
   • Prism surface：
     • After each measurement, useLint-free clothorSpecial mirror cleaning paperDip a small amountdistilled waterorisopropanolGently wipe (concentration ≤ 70%) to avoid scratches.
     • Prohibit the use of strong solvents such as alcohol and acetone, which may corrode prism coatings; If contaminated with oil, it can be cleaned with neutral detergent and immediately wiped dry.
   • Light source window：
     • Check the window of the light source (such as LED or halogen lamp) for dust accumulation every month, blow it clean with compressed air or gently sweep it with a soft bristled brush to prevent measurement errors caused by light attenuation.
   • Flow pool (online)：
     • If the equipment is used for continuous monitoring of pipelines, it is necessary to check the circulation pool daily for bubbles, sediment, or particulate matter. If there is any, the injection valve needs to be closed and rinsed back with distilled water for 10 minutes until clear water is discharged.
2. Anti clogging treatment
   • Sample pretreatment：
     • Samples with high viscosity or containing solid particles (such as sauce or syrup) need to be pre treated through a filter (pore size ≤ 50 μ m) to prevent clogging of the flow cell or damage to the prism.
   • Backwash function：
     • Some online devices are equipped with backwash interfaces, and it is recommended to perform a backwash procedure once a week (such as circulating distilled water at 1.5 times the working pressure for 10 minutes) to remove residues.

2、 Regular calibration and verification

1. calibration cycle
   • Daily verificationAfter turning on the device daily, usestandard solutionSingle point validation should be conducted using sucrose solutions Brix 20% and 40%, with an error of ≤± 0.1 ° Brix.
   • Comprehensive calibrationEvery 3 months or when changing production batches, useTwo-point calibration method(such as Brix 0% and Brix 50%), covering the device range.
   • Mandatory calibrationIf the equipment undergoes maintenance, replacement of optical components, or environmental temperature fluctuations greater than 10 ℃, it needs to be recalibrated immediately.
2. Calibration steps
   • Environment PreparationPlace the device in a constant temperature (20 ± 2 ℃), vibration free environment and stabilize for 30 minutes.
   • Standard solution preparation：
     • Weigh sucrose (AR grade) using an analytical balance, prepare Brix standard solution according to international standards (ICUMSA), or purchase certified standard solution directly (such as Hanna Instruments, Reagecon).
   • Calibration operation：
     1. Enter calibration mode and input the concentration value of the standard solution.
     2. Inject the standard solution into the flow cell or drop it onto the surface of the prism, and wait for the reading to stabilize (usually 30 seconds).
     3. Confirm that the deviation between the displayed value and the standard value is ≤± 0.05 ° Brix, otherwise adjust the calibration coefficient or contact after-sales service.

3、 Environmental Control and Protection

1. temperature management
   • Operating TemperatureEnsure that the equipment operates within the range of 5-40 ℃, and activate the temperature control module (such as semiconductor heating/cooling chips) when it exceeds the range.
   • temperature compensationIf the difference between the sample temperature and the calibration temperature is greater than 5 ℃, the automatic temperature compensation (ATC) function should be enabled, or the temperature value should be manually entered for correction.
2. Anti corrosion measures
   • Acid alkali sample processingAfter measuring strongly acidic (pH<3) or strongly alkaline (pH>11) solutions, immediately rinse the flow tank with distilled water to prevent corrosion of the sensor.
   • Organic solvent protectionAvoid measuring samples containing organic solvents such as ethanol and acetone. If necessary, choose solvent resistant models (such as stainless steel flow cells and fluororubber seals).
3. Dust and moisture prevention
   • Installation locationThe equipment should be kept away from dust sources (such as crushers, packaging lines), or equipped with dust covers (IP54 or above level).
   • humidity controlThe relative humidity should be maintained at 30%~85%. If it is in a high humidity environment for a long time (such as a brewing workshop), it is necessary to regularly use desiccants for dehumidification or activate the heating function.

4、 Electrical and Mechanical Inspection

1. Power supply and grounding
   • Use independent power sockets to avoid sharing power lines with high-power devices such as motors and compressors, and prevent voltage fluctuations from interfering.
   • Ensure that the equipment is well grounded with a grounding resistance of ≤ 4 Ω to prevent static electricity or leakage from damaging the circuit.
2. Tightening of connecting components
   • Every month, check whether the connection parts of the circulation pool, sensors, communication cables, etc. are loose, especially for online equipment, and confirm that there is no leakage at the pipeline joints.
   • If aging or cracking of the sealing ring is found, it should be replaced immediately (such as silicone sealing rings, which usually have a lifespan of 2-3 years).
3. Mechanical vibration protection
   • Avoid installing equipment near vibration sources such as pumps and centrifuges. If unavoidable, install shock absorbers (such as rubber isolators).

5、 Software and Data Management

1. Firmware Update
   • Check the manufacturer every 6 months, download the latest firmware version, fix known vulnerabilities, and optimize algorithms (such as improving anti-interference capabilities).
   • Backup device configuration parameters before updating to avoid data loss.
2. Data storage and backup
   • Online devices are usually equipped with data recording functions. It is recommended to export historical data to a local server or cloud platform every week in CSV or Excel format for easy analysis.
   • Set a data retention period (such as 1 year) and regularly clean up expired data to free up storage space.

6、 Long term shutdown and restart

1. Pre processing before discontinuation
   • Clean the circulation pool and prism, blow off the internal moisture with dry nitrogen gas to prevent mold growth.
   • Remove the battery (if removable) to avoid leakage and corrosion of the circuit.
   • Store in the original packaging box at a temperature of 5-25 ℃, humidity<60%, and avoid direct sunlight.
2. Check before restart
   • After reinstallation, power on and run the device without load for 2 hours, and observe whether the self check of the equipment passes (such as whether the light source is normal and whether the communication is stable).
   • Perform a complete calibration and confirm that the accuracy meets the requirements before putting it into use.

7、 Common faults and solutions