Product Overview

This curing box is developed, designed, and manufactured in accordance with the national standard GB 1345-77, “Test Methods for Standard Consistency Water Requirement, Setting Time, and Volume Stability of Cement,” as well as technical data provided by the National Building Materials Research Institute and other relevant authorities. It is suitable for large, medium, and small cement plants, as well as for use by construction and civil engineering departments in the curing of concrete and cement setting specimens.

Based on the original curing chamber, this equipment has undergone a series of improvements in its overall design and internal structure. The chamber door is sealed with magnetic sealing strips, and the interior is equipped with both cooling and heating units, offering a range of advantages such as an aesthetically pleasing appearance and high precision in temperature and humidity control.

Main Technical Specifications

Working Principle and Structure

1. Structure

The chamber consists of an inner and an outer shell. The outer shell is fabricated from high-quality cold-rolled steel sheet, while the inner shell is constructed from acid- and alkali-resistant imported stainless steel or plastic panels. The shelving is made from aluminum alloy profiles, offering excellent corrosion resistance. The inner chamber is primarily used for heating and auxiliary humidification; the humidification system relies mainly on ultrasonic humidifiers, with water-heating evaporation as a supplementary method. The automatic control system comprises temperature- and humidity-control instruments that automatically switch among cooling, heating, and humidification based on the set temperature and humidity values. Temperature and humidity within the chamber are displayed digitally on the instruments.

2. Operating Principle

Temperature: When the chamber temperature falls below the setpoint specified by the thermostat, the thermostat outputs a heating signal, activating the electric heating element. Conversely, when the temperature exceeds the setpoint, the thermostat commands the refrigeration system to operate. Once the desired temperature is reached, heating or cooling automatically ceases.

Humidity Control: An ultrasonic humidifier is used to increase humidity, ensuring that the chamber humidity reaches ≥95% RH. The humidity controller automatically operates the humidification system; when the relative humidity falls below 90% RH, the temperature controller activates the heating element, which ceases operation automatically once the set hysteresis value is reached.

How to use

1. After the cabinet has been in place and stationary for 24 hours, turn on the power switch; no need to add water to the water tank.

2. Open the rear door, remove the humidifier nozzle, take out the water tank, unscrew the bottom cover of the tank counterclockwise, fill the tank completely with purified water (distilled water is preferred), tighten the cover, reattach the tank to the humidifier, turn on the power switch, and set the mist adjustment knob to the maximum position. The instrument’s temperature and humidity settings have been pre-adjusted at the factory.

3. This instrument achieves automatic temperature control simply by setting the desired temperature.

4. Connect the power supply to start the instrument. Once the chamber’s temperature and humidity have reached the set values, place the test specimen inside. Heating and cooling must never be operated simultaneously.

Precautions

Read the instruction manual carefully before use.

1. The enclosure shall be used in a well-ventilated, dry, level, and non-corrosive environment.

2. After the cabinet is in place, it must remain stationary for 24 hours before being powered on. A stable-voltage power supply must be used, and the compressor must be allowed to rest for at least 3 minutes after shutdown to ensure its normal service life.

Common Faults and Troubleshooting Methods

(1) The instrument does not display or is not functioning.

(2) With the power supply turned on, inspect the fuse and plug.

(3) The power switch is faulty; replace it with a new one.

(4) Instrument output and input cables are disconnected, or the plugs are not fully inserted.

(5) The contactor is burnt out; replace it with a contactor of the same model.

2. The instrument is not cooling.

(1) Verify that the setpoint on the temperature controller is correct; if the controller is not outputting a signal, adjust the setpoint or check the controller’s fuse.

(2) If the temperature controller outputs a signal but the contactor does not operate, replace the contactor.

3. Refrigerant Leakage

If the compressor does not operate, connect it directly to the power supply; if it still fails to run, the compressor is likely burnt out and must be replaced.

4. The entire unit does not heat up.

(1) If the temperature controller is damaged, it must be replaced with an electric heating element of the same power rating.

5. Do not add humidity if the chamber temperature is below the setpoint.

(1) Verify that the setpoint is correct.

(2) When the digital display reading falls below the setpoint, does the humidifier control unit indicator light turn yellow? If it does not, the hysteresis value should be appropriately reduced so that the light turns red when no additional humidification is required; otherwise, the humidifier itself should be inspected.

(3) If the humidifier is not functioning properly, first check the transducer for scale and impurities; the transducer must be kept clean. Next, verify that the water tank is adequately filled—since the humidifier is equipped with a water-level probe that automatically protects the transducer, the unit will automatically stop misting if the water supply is interrupted.

(4) If the temperature controller fails to output a signal, the instrument should be inspected. When the humidity display reads between 01% and 100%, this is not considered an abnormal condition; simply wiping the dry-bulb probe of the temperature sensor with a dry cloth will restore normal display. The wet-bulb sensor should be checked regularly.

5. The magnetic strip is not tightly sealed.

Use a heating method to widen the magnetic stripe (with a hair dryer).

Instructions for Use of the Temperature and Humidity Controller

1. Temperature measurement range: 20–25°C

2. Temperature measurement accuracy: ±2°C

3. Humidity measurement range: 50–90% RH 4. Humidity measurement accuracy: ±5% RH

5. Automatic Clock

6. External control configuration is supported.

7. Time for print output can be set externally.

8. Operating environment: ≤50°C, ≤85% RH

Special Precautions

1. Do not add water to the water tank inside the instrument case.

2. The humidifier must be filled with distilled water.

3. Whenever water is added to any component, the power must be turned off first.

4. For every shift exceeding 12 hours, the water tank humidifier must be checked to ensure it is adequately filled with water.

5. When filling the humidifier with water, please handle it carefully to prevent damage.

6. All of the above must be strictly in accordance with the operating procedures; otherwise, you shall bear all consequences.