Low Temperature Thermostatic Bath

A. Instrument Appearance Introduction

A diagram illustrates the instrument's front and back panels. The front panel features controls labeled 'Power key', 'The instrument set key', 'The shift key', 'The reduction key', 'The addend key', 'The circular key', and 'Refrigeration key', connected to a 'Control box'. The back panel shows 'power insurance', 'general supply', 'Circulation Insurance', 'Water Inlet', and 'Water outlet'.

B. Features

• Refrigeration system: low noise air-cooled totally enclosed compressor unit, offering fast refrigeration speed and strong temperature stability.
• Control system: utilizes the latest special software, self-made temperature control technology, equipped with high standard PT100 and fully imported electronic components.
• Circulation system: comprises internal and external circulation. External circulation allows the constant temperature liquid in the tank to be introduced outside, establishing a second constant temperature field, or serving as a cold source to cool experimental containers. Internal circulation ensures uniform and stable liquid temperature within the tank.
• Protection system: the refrigeration includes overheating and overcurrent protection. The control system features over-temperature alarm, adjustable upper and lower temperature limits, and automatic load cutoff during over-temperature events.
• Display and Control: High-end large screen LCD control instrument with a resolution of 0.01 °C, offering simple function operation and strong temperature stability. PID control can automatically search or be manually adjusted.
• Accuracy: The accurate temperature correction function can reach 0.01 °C, and the maximum temperature fluctuation is ± 0.02-0.05 °C (depending on the model).

C. Technique Parameter

D. Operating Steps

1. Connect the circulating pump before startup (this step can be omitted if there is no water inlet and outlet):
   • 1.1 For internal circulation, connect the water outlet and water inlet directly with both ends of the supplied hose.
   • 1.2 For external circulation, connect the water outlet to the inlet of the container/equipment outside the tank with a hose, and connect the water inlet to the outlet of the container/equipment outside the tank.
2. Add the corresponding liquid medium into the tank. The liquid level shall not be 20mm lower than the worktable to avoid damage caused by exposed dry burning of the heater.
   • 2.1 When the working temperature is lower than 8 °C, the liquid medium is generally industrial alcohol or antifreeze.
   • 2.2 When the working temperature is between 8 °C and 75 °C, the liquid medium is generally purified water.
   • 2.3 When the working temperature is above 75 °C, dimethyl silicone oil with a viscosity of 50cs is generally selected as the liquid medium.
3. Plug in the power. Turn on the "main power" switch (located on the back of the instrument), and then turn on the "power" button on the operation panel.
4. Perform instrument operation:

   4.1 Display Description

   A diagram depicts the instrument's control panel interface. It includes a 'Main Interface' area with sections for 'SET', 'Self Diag', and 'Time Unit'. A 'TIME ZONE' and 'DISPLAY ZONE' are present, along with a 'SETTING ZONE'. Key operational buttons are labeled 'Power', 'Cooling', 'Circulate', 'SET', 'Run Stop', 'Cir Heat Cool', 'Alarm', and directional arrow keys.

   4.2 Description of instrument keys

   • Set: set function key, shift key
   • ▼: decrease key
   • ▲: increase key

   4.3 Setting of temperature parameters:

   • Press the `set` key to enter the setting state for the temperature value. The last value of the setting temperature "SV" will flash on the display.
   • First, press the `shift` key, then use the plus (▲) or minus (▼) key to set the desired working temperature.
   • Press the `set` key once more. The last value of the timed shutdown time (min) "0000" will flash in the upper right corner of the display. If the default "0000" is not needed, press the `set` key again to exit parameter setting and save the value. The display "PV" will then show the current liquid medium temperature in the tank.

   5. Operation after parameter setting:

   After the temperature parameter setting is completed, first open the "cycle" button on the operation panel, and then open the "refrigeration" button. (Note: when the working temperature exceeds 40 °C, the compressor automatically enters protection mode and refrigeration does not start). The microcomputer then enters the automatic control state.

   6. Description of correction between measured temperature and actual temperature:

   • In the normal display state, long press the `set` key for 3 seconds. The password prompt "LC" will be displayed in the upper row of the display window, and the password value in the lower row.
   • Press the `▲` key to enter the password "00000 3".
   • Click the `set` key to enter the internal parameter setting state.
   • Click the `set` key again to select the parameters to be modified. Look for the indicator "PB1" in the upper window; this is the temperature correction interface.
   • If the actual temperature is higher than the displayed temperature, press the `▲` key to increase. If lower, press the `▼` key to decrease.
   • Long press the `set` key for 3 seconds to automatically save the parameter values and exit this state.
   • The experiment or test can be carried out when the measured value "PV" reaches the working temperature and stabilizes for 15 minutes.

E. Precautions for use

1. Liquid medium shall be added into the tank before use, and air opening is strictly prohibited. (Note: the liquid shall not contain acid and alkali).
2. The power supply power shall be greater than the total power of the instrument, and the power supply must have a good "grounding" device. The voltage used shall be subject to the technical parameter table.
3. The instrument shall be placed in a ventilated and dry place, and the back and both sides shall be 300mm away from obstacles to maintain good heat dissipation.

After use, set all switches to the off state, unplug the power plug, open the drain valve, discharge the medium in the tank, and keep the tank dry and tidy.

F. Packing list

• 1 main energy: 1set
• 2 cover plate: 1piece
• 3 specification: 1piece