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Terminology for reliability testing equipment of environmental test chambers

2023-03-20

1. Test equipment volume

The actual volume of the space limited by the inner wall of the environmental test chamber, expressed in m3 (or L).

2. Workspaces

The portion of space in a high and low temperature test chamber that can maintain the specified test conditions within the specified deviation range.

3. Stable state of the test chamber

The state when the self variation of any point in the working space of the test box meets the performance requirements of the equipment itself.

4. Temperature deviation

Under the stable state of the test chamber, the temperature difference between the highest and lowest temperatures measured at each measuring point in the working space and the nominal temperature within the specified time.

5. Relative humidity temperature difference

Under the stable state of the test chamber, the maximum relative humidity and minimum relative humidity measured at each measurement point in the workspace within the specified time are the upper and lower deviations from the nominal relative humidity.

6. Temperature fluctuation

The change in relative humidity at any point in the working space over time during a specified time interval in a stable state of the test chamber.

7. Relative temperature fluctuation

The change in relative humidity at any point in the workspace over time within a specified time interval.

8. Temperature uniformity

The maximum difference in temperature between any two points at a certain instant in the working space under the stable state of the test chamber.

Calculation method: under stable state, the arithmetic mean value between the measured maximum temperature and the measured minimum temperature at each measuring point in the working space within 30min.

9. Relative humidity uniformity

The maximum difference in humidity between any two points at a certain instant in the working space under the stable state of the test chamber. Calculation method: under stable state, the arithmetic mean value between the measured maximum temperature and minimum humidity at each measurement point in the working space within 30 minutes.

10. Temperature change rate

The transformation rate between two specified temperatures measured at the geometric center point of the working space of the test chamber, expressed in ℃/min.

11. Average rate of temperature change every 5 minutes

The average transformation rate between two specified temperatures measured at the geometric center point of the working space of the test chamber every 5 minutes, expressed in ℃/min.

12. Barometric deviation

In a stable state, the test chamber measures the deviation between the maximum and minimum air pressure measured at the measuring point in the working space and the nominal air pressure within the specified time.

13. Pressure change rate

The transition rate between two specified air pressures measured at the geometric center point of the working space of the test chamber, expressed in kPa/min.

14. Temperature recovery time

After reaching a stable state at the specified temperature, the time required for the temperature of the working space to recover from being loaded to the original stable state.

15. Temperature overshoot

When the equipment heats up or cools down to the specified temperature, the actual temperature of the working space exceeds the allowable deviation range of the specified temperature.