Definition
Stirring thermostatic tank is a commonly used equipment in laboratories that provides a uniform and stable liquid environment for samples or reaction vessels by combining heating or refrigeration systems with stirring devices. It is widely used in physicochemical experiments, material testing, biological culture (non-medical fields), and various sample preparation processes that require precise temperature control.
Principle
The core working principle of the stirring thermostatic sink is based on thermodynamic equilibrium and fluid dynamics. The equipment usually consists of a tank, a temperature control system, a stirring system and a circulation system. The temperature sensor monitors the temperature of the liquid in the tank in real time and feeds the signal back to the controller. The controller works by comparing the set temperature with the measured temperature to drive the heater or refrigeration unit to maintain the target temperature. At the same time, the built-in agitator works continuously to promote the flow of liquid in the tank, effectively reducing temperature stratification and ensuring a high degree of uniformity in the temperature of the working area. Its temperature control process can be simplified into a closed-loop feedback system.
Measurement and calibration methods
The evaluation of the performance of the stirring thermostatic sink mainly focuses on temperature accuracy, uniformity and stability. When measuring, it should be carried out in accordance with relevant national standards or international standards (such as JJF 1030-2010 "Technical Performance Test Specification for Thermostatic Tanks"). Meter-calibrated multi-point temperature probes, such as platinum resistance thermometers, are typically used to be placed in different locations in the tank work area. In the steady state, the temperature value of each point is recorded to calculate the regional uniformity. Change in temperature at a certain point is recorded over a period of time to assess temperature fluctuations (stability). Calibration cycles are recommended to be performed regularly depending on the frequency of use and criticality.
Influencing factors
The performance of a stirring thermostatic sink is affected by various factors. Environmental conditions, such as ambient temperature fluctuations and ventilation, can interfere with the thermal insulation and temperature control efficiency of the tank. The selection of medium in the tank is very important, water has a large specific heat capacity and low cost, which is a commonly used medium; However, for higher or lower temperature ranges, silicone oil, glycol solution and other media need to be selected. The stirring speed is set directly to the temperature uniformity, with low speeds leading to uneven heat distribution and high speeds causing violent fluctuations or bubbles. In addition, loading, i.e., the number of samples placed in the tank, the material, and the heat capacity, can also affect the thermal balance of the system, affecting the temperature response speed and ultimate stability.
Main application areas:
In the field of scientific research and industrial testing, stirring thermostatic tanks play an important role. In chemistry, it provides a constant temperature environment for synthesis reactions, viscosity determination, and solubility studies. In materials science, it is used for thermal properties testing of polymer materials, coating curing, and other processes. In the food industry, it can be used to detect the melting point of fats and fats and study the thermal stability of food ingredients. In terms of environmental monitoring, it supports pretreatment steps such as sample thermostatic extraction and microbial culture (non-pathogens). At the heart of its application is to provide a reliable and controlled temperature platform for various experiments.
Key points to consider in selection
When choosing a stirring thermostatic sink, you need to consider systematically. The primary parameters are the temperature range and temperature control accuracy, which should be determined according to the experimental needs and leave a certain margin. The volume of the tank and the working size should be adapted to the commonly used laboratory utensils. Temperature uniformity and stability are key indicators of equipment performance and should be based on the test data provided by the manufacturer. The mixing method and speed control range should meet the requirements of uniform mixing of the medium. The safety features of the equipment, such as overheating protection and low level alarms, should not be overlooked. In addition, energy efficiency, operating noise, ease of maintenance, and availability of subsequent calibration services are also considered. Evaluating these factors comprehensively will help you choose the right equipment for your actual work.