by - OBJECTIVE:
To lay down a procedure for operation of vernier calipers.
- SCOPE:
This procedure is applicable for procedure for operation of vernier calipers.
- RESPONSIBILITY:
QC Officer/ QC Executive
- ACCOUNTABILITY:
QC Manager
- PROCEDURE:
Clamping Screw:
Tighten the screw to lock the reading when you have to remove the caliper before reading.
Fine Adjustment:
This is used to control the measuring force. Tighten the clamping screw of the fine adjustment; rotate the adjusting screw to let the measuring faces be in good contact with the work piece, meanwhile the clamping screw must be loose.
Precaution for measurement:
It is important to apply suitable measuring force on the caliper to get accurate reading. Always use knob for the fine adjustment of vernier caliper. Take care to avoid parallax error when reading the vernier scale. Parallax error is caused when viewing from A direction. Please view from B direction. In order to get smooth sliding, rotate the adjusting screw of the fine adjustment to make the fine adjustment close to the vernier before sliding.
Calibration:
Calibration of vernier caliper is done by external government approved testing laboratory.
Calibration frequency is annually.
Precautions:
Clean the caliper before use.
Make sure the measuring faces are clean.
Remove cutting chips, dust, burrs and other foreign substances from the piece to be measured.
Make sure that the zero lines of the vernier scale coincide with the zero lines of the main scale when the external jaws are closed. Make sure that no slit is observed between two external jaws when they are closed.
Vernier caliper body should be lubricated with a small amount of clock oil.
Measuring faces should be carefully protected from being scratched, hit or rusty.
Do not operate abruptly, drop or shake caliper.
- TRAINING:
Trainer : Manager – Quality Control
Trainees : Staff of the QC departments
- DISTRIBUTION:
Master Copy : QA Department
Controlled Copy : QC Department
Display Copy : QC Department
- REFERENCES:
In-House
