High and low temperature alternating test chamberThe core operation process of the safety operation regulations revolves around four core steps: "preparation before operation → parameter setting and startup → operation monitoring → shutdown and closure". Each step is accompanied by safety protection requirements, and the specific process is as follows:

1、 Preparation before operation (safety first, indispensable)

Environmental safety verification: Confirm that the test area is well ventilated, free of flammable and explosive materials/corrosive gases, the ground is flat and slip resistant, and equipped with effective dry powder fire extinguishers; The distance between the equipment and the wall/other equipment is ≥ 50cm, and the environmental temperature and humidity meet the requirements (15-30 ℃, humidity ≤ 85% RH).

Equipment safety inspection:

Appearance and wiring: The shell is undamaged, the insulation layer of the power/data line is not aged or cracked, and the grounding is reliable (grounding resistance ≤ 50 Ω);

Core components: The sealing strip of the box door is intact, the locking mechanism is flexible, there is no leakage in the refrigeration pipeline, and the water level in the water tank reaches the "high" mark;

Safety device: The emergency stop button, over temperature alarm, leakage protector and other functions are normal. Pressing the emergency stop button will immediately cut off the power.

Personnel and sample preparation: Operators should wear non slip shoes and protective gloves (volatile samples need to wear masks/gas masks); The surface of the sample needs to be cleaned of oil and dust. It is strictly prohibited to place flammable, explosive, toxic, or corrosive samples. The size should not exceed 80% of the furnace volume and should not obstruct the air duct and sensors.

2、 Parameter setting and startup (precise and standardized to avoid misoperation)

Equipment self-test: Connect the main power supply, open the control panel, wait for the equipment self-test to complete, and confirm that the instrument has no fault alarms and displays normally.

Parameter setting: Set the high temperature value, low temperature value, alternating cycle, insulation time, and number of cycles according to the test standards (such as GB/T 2423.1-2008); Strictly follow the rated range of the equipment, with a heating rate of ≤ 5 ℃/min and a cooling rate of ≤ 3 ℃/min, and select safety options such as "over temperature protection" and "water cut-off protection".

Pre cooling/preheating and sample placement: Click on "Pre cooling/preheating", wait for the temperature inside the furnace to approach the initial set value (deviation ≤± 5 ℃) and stabilize, open the box door and place the sample steadily, ensuring that the distance between the sample and the box wall/sample rack is ≥ 3cm and does not touch the heating tube/refrigeration components; Close the box door and tighten the lock to confirm good sealing.

Start operation: After verifying the parameters are correct, click the "Start" button and observe whether the equipment is running according to the set curve. After the temperature fluctuates normally, the operator can leave the monitoring area.

3、 Running process monitoring (dynamic monitoring, timely handling of anomalies)

Regular recording: Record the temperature and operating status of the furnace every 30 minutes to ensure that the temperature deviation is ≤ ± 2 ℃ and there are no abnormal noises or odors.

Exception handling:

If there is an alarm for overheating, water leakage, or electric leakage, immediately click "pause" or press the emergency stop button directly;

Overtemperature alarm: troubleshoot sensor faults, short circuits in heating tubes, calibrate temperature and restart;

Leakage alarm: Power off to check the pipeline/water tank, repair and replace the water quality;

Leakage alarm: Immediately cut off power, have professional personnel inspect the circuit, and prohibit self disassembly and repair.

Forbidden operation: It is strictly prohibited to open the box door during operation; If it is necessary to take or place samples, the test should be paused first. After the temperature in the furnace drops below 50 ℃ and the pressure returns to normal pressure, wear high-temperature protective gloves for operation.

4High and low temperature alternating test chamberShutdown and Closing (Standardize Closed Loop, Protect Equipment)

Normal shutdown: After the experiment is completed, the equipment will automatically shut down or manually click "shutdown". Wait for the temperature inside the furnace to naturally drop to 20-25 ℃ (forced rapid cooling is strictly prohibited), and then turn off the control power and main power in sequence.

Sample retrieval: Wear protective gloves and open the box door to slowly retrieve the sample, avoiding condensation from falling onto the circuit components. Record the final state of the sample.

Equipment cleaning: Use a dry soft cloth to wipe the inner wall of the furnace body, sample rack, and sealing strip. Oil stains should be wiped with a neutral cleaner and dried; Clean up the surrounding environment of the equipment to avoid dust accumulation.

Record archiving: Fill out the "Equipment Operation Record Form", indicating the operating time, parameters, abnormal situations, and handling results, and organize the test data.