The accuracy of the grain moisture analyzer directly affects the quality control of grain procurement, storage, and processing. Its calibration, verification, and error control need to follow standardized processes.

1、 Calibration strategy

Single point calibration

Use standard weights (such as 100g) for weight calibration. The operation steps are as follows: After zeroing the instrument, enter the settings - calibration settings - single point calibration interface, place the weight when the value flashes, and complete the calibration after the weighing is stable. This process can correct the deviation of the weighing sensor and ensure the accuracy of the basic measurement.

temperature calibration

For heating type instruments (such as halogen lamp heating type), temperature control accuracy needs to be verified. When using a high-precision thermometer to compare the instrument display value with the actual value, if the deviation exceeds ± 1 ℃, the temperature sensor parameters need to be adjusted.

2、 Verification method

Standard sample validation

Use standard samples with known moisture content (such as 12.5% moisture content corn flour) for testing, and repeat three times to take the average value. If the deviation between the result and the standard value is ≤± 0.5%, the verification is passed; Otherwise, recalibration is required.

Comparative experimental verification

Compared with the national standard oven method (105 ℃ constant weight method), 10 samples were randomly selected for synchronous testing. If the moisture difference is ≤ ± 1%, the reliability of the instrument meets the standard.

3、 Error control strategy

Environmental factor control

Maintain a laboratory temperature of 20-25 ℃ and humidity of ≤ 60%, avoid direct blowing of instruments by air conditioning or fans, and reduce the interference of airflow on weighing.

Sample processing optimization

Crush the sample to a uniform particle size (such as passing through a 40 mesh sieve) to ensure consistency in water evaporation; Control the loading amount (sample layer thickness ≤ 5mm) to avoid accumulation and evaporation of internal moisture.

Strengthening operational standards

Strictly follow the instructions, such as closing the lid tightly before heating to prevent moisture from escaping; After testing, wait for the instrument to cool down to below 40 ℃ before sampling the tray to avoid thermal deformation affecting weighing.