Height caliperThe calibration of should follow a strict standard process, covering three core links: preliminary preparation, calibration implementation, and result processing. The specific specifications are as follows:
1、 Preliminary preparation
environmental conditions
Temperature: 20 ℃± 5 ℃ (to avoid thermal expansion and contraction affecting accuracy).
Humidity: ≤ 80% RH (to prevent electronic components from getting damp or metal parts from rusting).
Cleanliness: No vibration, no dust, ensuring that the measuring reference surface is free of contamination.
Calibration tool
Standard gauge block: Select a 0-level or 1-level precision gauge block based on the height caliper range.
Calibration platform: marble or cast iron platform, flatness error ≤ 0.005mm.
Cleaning tools: dust-free cloth, alcohol (used to clean calipers and measuring blocks).
Recording tools: calibration record sheet, pen.
Equipment inspection
Appearance inspection: Confirm that the caliper has no cracks, rust, scratches, and clear markings.
Function check: Check whether the sliding is smooth, whether the locking device is effective, and whether the digital display is normal (such as an electronic caliper).
Isothermal treatment: Place the caliper and gauge block in the calibration environment for at least 2 hours to eliminate temperature differences.
2、 Calibration implementation
Zero calibration
Translate into EnglishHeight caliperThe measuring claw (or probe) gently touches the surface of the platform.
Adjust the zero position of the caliper to reset the scale to zero (or display the number as 0.00mm), ensuring that the measuring claw is in close contact with the platform surface without any gaps.
Repeat 3 times and take the average as the zero position benchmark.
Calibration of indication error
Calibration point selection: Select at least 5 calibration points evenly distributed within the range (such as 0mm, 50mm, 100mm, 150mm, 200mm).
Operation steps:
Place standard measuring blocks (such as 5mm, 10mm, 20mm, etc.) on the platform.
Measure the height of the measuring block with a height caliper and record the caliper reading.
Calculate the indication error: Error=Caliper indication - Gauge block standard value (Example: Gauge block standard value 10.000mm, caliper indication value 10.002mm, error+0.002mm).
The error must be within the allowable range (for example, for calipers with an accuracy level of 0.02mm, the allowable indication error is ≤± 0.02mm).
Repetitive calibration
Repeat the measurement 5 times at the same calibration point (e.g. 100mm).
Record each indication and calculate the difference between the maximum and minimum values (e.g. measured value 100.001) mm、100.002mm、100.001mm、100.002mm、100.001mm， The repeatability error is 0.001mm.
The repeatability error must meet the requirements (such as ≤ 0.005mm).
Parallelism calibration
Fix the caliper on the platform and measure the claws to touch two parallel planes (such as the side of the measuring block).
Record the measurement values and calculate the parallelism error.
The error should be within the allowable range (such as ≤ 0.03mm).
3、 Result processing
Error adjustment
If the error exceeds the allowable range, the caliper needs to be adjusted (such as fine-tuning the zero position screw, cleaning the measuring claw).
Adjust and recalibrate until the error meets the requirements.
Record and Report
Record the calibration date, environmental conditions, calibration personnel, calibration points, standard values, caliper readings, error values, qualification and adjustment status.
Provide a calibration certificate indicating the validity period (usually 1 year).
Nonconforming product handling
Repair or scrap unqualified calipers.
Regular (such as monthly) simple checks are conducted to ensure long-term stability.