Whenever we talk about temperature accuracy, it should be clear which items are meant and in what range.

Display resolution:

All devices have a temperature display that shows the temperature inside the chamber. The accuracy of the display means the tolerance with which the display shows the temperature of the chamber.

For example, when the device board shows 37 degrees, what is the temperature inside the chamber? This difference is called the accuracy of the display. The lower it is, the more accurate the performance of the display.

This accuracy has nothing to do with the temperature fluctuation. For example, the device can have a very accurate display, but the temperature inside the chamber fluctuates a lot.

Thermal stability:

Laboratory chambers have a controller that controls and keeps the temperature inside the chamber at the user’s desired temperature.

The meaning of thermal stability is the fluctuation rate of the device at the set point temperature. The lower the stability number, the better the performance of the device. Nowadays, controllers are usually digital and use different methods to keep the temperature constant. Although some brands still use mechanical thermostats, which are less accurate than digital systems. It should be noted that the use of a digital controller or a microcontroller cannot guarantee the accurate performance of the controller. Other factors, such as control methods and programming skills, also play a role.

Although thermal stability is very important, it does not affect the isotherm of the device. This means that a device may be able to keep the temperature constant, but the temperature may differ in different parts of the chamber.

Uniformity:

One of the most important points in laboratory chambers is uniformity in different parts of the inner chamber. Uniformity means the same temperature in different device parts, called uniformity or isothermal accuracy.

It is obvious that the lower this number is, the better. Sometimes they use a circulating fan to improve the temperature. Still, it should be noted that the use of a circulating fan does not have a positive effect on the temperature of the device, the type of fan, the location of the fan, and The elements and the design of the internal structure of the device are also very important in uniformity.

Resolution:

One thing that sometimes needs clarification regarding the device’s accuracy is the device’s resolution. The meaning of the resolution of the steps is to measure and display the temperature. For example, a device whose resolution is 0.1 means that it displays and controls the temperature as a tenth of a tenth, and a device whose resolution is 1 degree displays the temperature by one degree. and controls

The lower resolution is better. In some devices, the resolution is 0.1 degrees at low temperatures and 1 degree at higher temperatures.

Another important point in discussing the accuracy of the user’s desired temperature range. The thermal accuracy is not the same in all ranges of the device. For example, the device may be very accurate at one temperature (37 degrees) and have a temperature difference at another (54). For this reason, reputable companies state temperature accuracy in different ranges separately. With the above explanations, it was found that the high-temperature accuracy of the device includes the correct operation of several parts, and only high accuracy in one part cannot call the device accurate.

Therefore, announcing the device with an accuracy of 0.1 degrees is fundamentally wrong. Why should it be determined which part this 0.1 corresponds to (display accuracy, thermal stability, uniformity)?

Sometimes it has even been observed that the device’s resolution is referred to as the device’s accuracy and causes problems for consumers.

Sometimes it has been observed that users try to check the device’s accuracy and the controller’s performance by placing a thermometer inside the device. But it should be noted that checking the device’s thermal performance requires special tools and special knowledge. Therefore, to do this, ask the calibration companies to check the device’s performance.
Calibration companies operate under the supervision of the standards department. After calibrating the device, they issue a calibration certificate and check its accuracy from different angles and temperatures.