The reasons for the deviation of the uniformity of the programmable high and low temperature box and the introduction of the humidification process

A natural environment experimental equipment, including the natural environment standard provided by the programmable high and low temperature box, must be observable and manipulable, this is not only to better limit the air quality parameters, within a certain time tolerance Within the scope, it is necessary to ensure the reproducibility and repeatability of the experimental standard, and it is also necessary to consider the safety of the commodity experiment, so as to avoid the destruction of the tested commodity due to the uncontrollable natural environment standard, resulting in unnecessary damage
.
Among the various experimental standards of the test box at this stage, it is generally stipulated that the precision of the main parameter detection should not be less than one-third of the error allowed by the experimental standard
.
The temperature uniformity is also one of the important technical parameters of the instrument box of the small rapid temperature change box.
When we use it, we may encounter the situation of uneven temperature.
So what is the reason for this problem?

1.
The overall structure
of the equipment The structure jeopardizes the uniformity of the mid-point temperature at work on a very large level
.
Because the structure is difficult to maintain symmetry, it is not harmful to deal with temperature uniformity
.
The gate is in front, the air-conditioning room is at the back of the box, the upper and lower air are exhausted, and the forced heat convection
.
This type of structure is symmetrical up and down, and it is easy to achieve uniform temperature on the left and right
.


2.
The airtightness of
the shell The airtightness of the shell is not very good, such as steam leakage at the gate, which will endanger the temperature uniformity of the equipment's personal studio
.

 
3.
Sample volume
If the test temperature error stipulates that the sample is placed in the room during the work, when the sample volume is too large, or the method or location of the sample is not appropriate, the air convection will be blocked, and a large temperature error will also be caused
.


4.
The heat conduction problem of the box wall is due to the heat conduction of the
instrument box of the small rapid temperature change box, which causes thermal damage such as heat leakage of the high temperature box or cold leakage of the low temperature box.
In order to better compensate for the thermal damage, there must be a difference in exhaust temperature.
The exhaust air temperature of the high temperature box is higher than the operating temperature in the box, and the exhaust air temperature of the instrument box of the small rapid temperature change box is lower than the operating temperature in the box
.
Because the temperature difference of the exhaust air must exist, the temperature in the working room will be uneven
.

 
Humidification water and power supply for small rapid temperature change box instruments Humidification water and power supply for
humid heat test chamber Humidification

is a very important part of small rapid temperature change box instruments and meters.
The current equipment humidification system is relatively complete.
Knowing the former Shijingshan of the device, the editor will share with you the previous humidification operation process of the device
.


A.
Installation of humidification water in the humid heat test chamber
1.
First, fill the recovery water tank with pure water or distilled water until it is about 90% full.
     2.

Check whether the boiling water valve is connected during maintenance.

After that, please pay attention to the water level of the replenishment tank and the water level controller, and keep the water level more than half at any time
.

4.
Supplement of humidification water; when the water level is insufficient, inject pure water or distilled water into the recovery water tank, and use a small water pump to pump the replenishment water tank to supply water for the automatic water circulation system
.


B: The power supply of the damp heat test box
1.
Pay attention to the power supply capacity, do not use more than one machine at the same time, so as not to cause a voltage drop to affect the performance of the machine, or even cause a breakdown.

2.
The grounding terminal at the rear of the machine, please ground it The wire must be properly constructed.
According to the technical guidelines for electrical equipment, the third is the grounding project.
The grounding resistance should be kept below 50Ω, and the diameter of the grounding wire is: 8mm2