Height caliperAs a precision measuring tool, it is widely used in fields such as mechanical processing and mold manufacturing. To ensure the accuracy of measurement results, regular calibration is required. The following are the calibration steps for height calipers, which are divided into three parts: preliminary preparation, calibration implementation, and result processing.
1、 Preliminary preparation
Calibration environment requirements
Temperature: 20 ℃± 5 ℃ (to avoid thermal expansion and contraction affecting measurement 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 equipment and tools
Standard measuring block: Select the appropriate accuracy level (such as level 0 or level 1) based on the height caliper range.
Platform: Marble or cast iron platform, with a flatness error of ≤ 0.005mm.
Cleaning tools: dust-free cloth, alcohol (used to clean calipers and measuring blocks).
Recording tools: calibration record sheet, pen.
Checked by calibrated height caliper
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).
2、 Calibration implementation
1. Zero calibration
Operation steps:
Gently touch the measuring claw (or probe) of the height caliper onto the surface of the platform.
Adjust the zero position of the caliper to zero the scale (or display the number as 0.00mm).
Notes:
Ensure that the measuring claw is in contact with the platform surface without any gaps.
Repeat 3 times and take the average as the zero position benchmark.
2. Calibration of indication error
Operation steps:
Select standard measuring blocks (such as 5mm, 10mm, 20mm, etc.) to cover the caliper range.
Place the measuring block on the platform and measure its height with a height caliper.
Record the caliper reading and compare it with the standard value of the gauge block to calculate the error.
Example:
Standard value of measuring block: 10.000mm
Caliper reading: 10.002mm
Error:+0.002mm (within the allowable error range, such as ± 0.01mm).
Calibration point selection:
Select at least 5 calibration points evenly distributed within the range (such as 0mm, 50mm, 100mm, 150mm, 200mm).
3. Repetitive calibration
Operation steps:
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.
Example:
Measurement values: 100.001mm, 100.002mm, 100.001mm, 100.002mm, 100.001mm
Repeatability error: 0.001mm (must meet repeatability requirements, such as ≤ 0.005mm).
4. Parallelism calibration (optional)
Applicable scenarios: occasions that require extremely high measurement accuracy.
Operation steps:
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.
3、 Result processing
Error judgment
Determine whether the error is within the allowable range based on the caliper accuracy level (such as 0.02mm, 0.01mm) and calibration specifications.
Example:
The height caliper with an accuracy level of 0.02mm allows an indication error of ≤± 0.02mm.
Adjustment and correction
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
Fill in the calibration record form, including:
Calibration date, environmental conditions, and calibration personnel.
Calibration points, standard values, caliper readings, and error values.
Whether it is qualified and the adjustment situation.
Provide a calibration certificate indicating the validity period (usually 1 year).
subsequent processing
Repair or scrap unqualified calipers.
Regular (such as monthly) simple checks are conducted to ensure long-term stability.
4、 Common problems and solutions
V. Summary
Height caliperThe calibration must be strictly operated in accordance with the specifications to ensure the accuracy of the environment, tools, and methods. The measurement accuracy of calipers can be effectively verified through steps such as zero position calibration, indication error calibration, and repeatability calibration. After calibration, the results should be recorded and processed in a timely manner to ensure reliable use of the caliper within its validity period.
Key points:
The calibration environment needs to be stable.
The accuracy of the standard gauge block should be higher than that of the calibrated caliper.
The error must be within the allowable range, otherwise it needs to be adjusted or repaired.
By following the above steps, the measurement reliability of the height caliper can be significantly improved, and quality problems caused by tool errors can be reduced.