Differences Between Equipment Calibration And Irradiance Adjustment

LIB aging test chamber has precise requirements for irradiance, temperature and relative humidity control to ensure the accuracy and reliability of test results. The reliability of the sensors and the data in question is particularly important. Therefore, the blackboard temperature, relative humidity and irradiance sensors need to be calibrated regularly. However, the boundaries of when to calibrate and when to make adjustments are often not clear to many customers.

Regarding the definition of calibration and adjustment, in "Basic and General Concepts of International Metrology Vocabulary and Related Terms", calibration and adjustment have completely different definitions:

Calibration: Under the specified conditions, based on a large number of uncertain values and reading results provided by the measurement standard, the correlation of the data is established, and then the information is used to establish the correlation to obtain from the reading Operation of test results.

Calibration should not be confused with the adjustment of the measurement system, which is often mistakenly referred to as "self-calibration" and should not be confused with calibration verification.

Adjustment: Adjustment refers to the change of the measurement system, or a series of setting modifications made in the measurement system to obtain a result consistent with the expected measurement value.

The main difference between calibration and adjustment is that calibration must be compared with known measurement standards, while adjustment is a modification to the measurement system in order to output the expected results.

Calibration and adjustment can be performed at the same time, but not necessarily at the same time, such as:

Compare the measurement system with the reference standard without changing the output instructions provided by the system;

The output of the measurement system has changed to meet customer expectations;

Compare the measurement system with the reference standard, and change the system settings to meet the requirements of the standard.

The discussion of calibration and adjustment is mainly based on the purpose of audit. Laboratory certifications such as ISO17025 have very specific requirements. One of them is that any representation of "calibration" must strictly adhere to the definition of calibration, that is, comparison with known reference standards. In addition, such comparisons must usually have "metrical traceability".

Although the terms "calibration" and "adjustment" have similar meanings, there are important differences between the two. Calibration involves comparing the measurement system with known measurement standards, while adjustment means that the output value of the measurement system has changed. In the case where the appropriate term is "adjustment", please use the word "calibration" carefully, because the difference between the terms is important for auditing and traceability.

Blow are calibration items and measurement methods of LIB xenon lamp aging test chamber:

Calibration Items

Temperature uniformity: ≤2 ℃; Temperature fluctuation: ≤0.5 ℃; Irradiation accuracy: ≤5% W / M2

Measurement method

1. Test the temperature with a special inspection instrument. The number and placement of temperature measurement points are bounded by the equipment workroom volume 2ml. When it is not greater than 2ml, it is 9 points, and when it is greater than 2ml, it is 15 points.

2. Measurement of temperature deviation

a) Install temperature sensors at each temperature measurement point.

b) Put the verification load evenly in the work space.

c) Heat temperature up to 35 ℃ and spray continuously.

d) After all temperature sensors reach 35 ° C and remain within the specified tolerance range, measure the temperature value of all measurement points once every 2min within 30min, and measure 15 times in total, and record them.

3. Detection Irradiation sensor current (5 ~ 24V), 10Ma.

The calibration validity period of the test chamber is generally 1 year. During long-term use of the test chamber, there will be wear and tear, which may cause deviations in test points. In order not to affect the test data, it is necessary to recalibrate and debug. Achieve uniform standards.

In order to ensure a good quality, all LIB test chambers machine in the factory will be strict calibration and commissioning. We provide test chambers, provide one stop test solution.

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