The fully automatic sealing machine is the core equipment for ensuring sample sealing in molecular biology experiments, and its calibration directly affects the quality of sealing and the reliability of experimental results. The following provides a detailed explanation of the standardized calibration process from preparation, testing, adjustment, to verification, in order to assist the laboratory in establishing a standardized operation and maintenance system.

1、 Preparation before calibration

1. Environmental and equipment verification

Ensure that the equipment is placed on a stable surface, away from vibration sources and strong magnetic field interference;

Check if the power supply voltage meets the range indicated on the equipment nameplate (within ± 5% fluctuation);

Clean the residual adhesive stains on the surface of the heating module to avoid affecting the temperature control accuracy.

2. Tool and consumables configuration

Tools: digital thermometer (accuracy ± 0.1 ℃), pressure tester, stopwatch, vernier caliper;

Calibration specific consumables: standard size PCR plate/eight tube, blank sealing film, thermosensitive film with known melting point.

3. Personnel qualification confirmation

Only technicians or certified engineers certified by the equipment manufacturer are allowed to perform calibration. Before operation, it is necessary to read the equipment manual thoroughly.

2、 Core calibration steps

Temperature control system calibration

Tightly attach the digital thermometer probe to the center of the heating module and set the target temperature (such as 176 ℃);

Start the heating program, compare the device display value with the measured value in real time, and continue monitoring for 5 minutes after the temperature stabilizes;

If the deviation is>± 2 ℃, enter the engineering mode through the touch screen to correct the PID parameters, and repeat the test until the error is ≤ ± 1 ℃.

Pressure system calibration

Install the pressure sensor onto the pressure head assembly and conduct a no-load pressure test using a standard thickness sealing film;

Adjust the pressure valve to make the pressure gauge display the default value of the equipment (usually 0.4-0.6MPa), and observe whether the pressure head drops uniformly;

Simulate different loads by adding or removing counterweights to verify the stability of pressure closed-loop control.

Sealing time calibration

Place the test film with fluorescent markers and set the shortest/longest sealing time;

After starting the device, use a stopwatch to time the actual action time, and the error between the actual action time and the set value should be less than 0.2 seconds;

Test continuously for 5 times, calculate the repeatability error, and recalibrate the motor step pulse if it exceeds the tolerance.

Verification of sealing effect

Select different specifications of consumables (single tube/row tube/deep hole plate) for film sealing test;

Check the flatness of the sealing film (visually without wrinkles), adhesive strength (the film cannot be peeled off by hand test), and edge integrity (without burn marks);

Measure the peeling force of the sealing film using a tensile tester, and the result should meet the requirements of ISO 11607 standard.

3、 Post calibration processing

All calibration data shall be recorded in the Equipment Calibration Record Form, including environmental temperature and humidity, measured values, adjustment amounts, and other information;

Paste the calibration qualification label and indicate the validity period (it is recommended to re calibrate every quarter);

If calibration fails, immediately stop using the equipment and report for repair. It is strictly prohibited to operate with defects.

4、 Key precautions

Unauthorized personnel are prohibited from accessing the equipment during the calibration process;

In humid environments, it is necessary to extend the preheating time to prevent condensation from affecting the circuit;

When replacing different batches of sealing film, it is necessary to re verify the optimal temperature/pressure parameters.

The precise calibration of the fully automatic film sealing machine is a key step in ensuring the reproducibility of experiments. Through a systematic calibration process, the membrane failure rate can be controlled within 0.3%, significantly improving the success rate of experiments such as qPCR and cell culture. It is recommended that the laboratory establish an annual calibration plan, combined with a daily inspection system, to build a complete equipment quality management system.