Touch1 LV Checkout Manual - Page 14
Appendix
The following information can be used a guide for setting up a formal calibration system in
your organization.
Calibration Standards
Calibration standards refer to written quality system requirements for organizations that
perform calibations and use calibrated equipment. Establishing a quality system according
to calibration standards helps insure calibrations are done competently and lends credibility
to the calibration organization. In the United States, common calibration standards include
ANSI/NCSL Z540-1, ISO/IEC Guide 25, ISO 10012-1, and the former MIL-STD 45662A.
The ANSI/NCSL Z540 standard refered to above, as well as other helpful metrology
information, can be obtained from the National Conference of Standards Laboratories
International (NCSL) at 1-303-440-3339 or
www.ncslinternational.org
. You can obtain the
ISO standards from the International Standards Organization (ISO) at their web site
www.iso.net/
.
The word “standards” is often used in another way in the metrology industry to refer to a
centralized, most accurate unit of measurement regulated by countries. The National
Institute of Standards and Technology (NIST) maintains the
national standards
for
measurements in the United States.
Good Calibration Practices
The calibration standards such as ANSI/NCSL Z540-1 and ISO 10012-1 require several
good practices for the calibration industry including the following areas:
Recall
System
How do you ensure you do not forget to send an instrument in for calibration? Use a
recall system which can be a card file or a computerized database. This system
includes calibration dates, due dates, calibration sources, and other instrument
records. The recall system ensures calibrated instruments are recalibrated in a timely
manner.
Calibration
Labels
How does someone know if an instrument has been calibrated without looking for the
paperwork in a filing cabinet drawer? When an instrument is calibrated, the calibration
standards require the instrument to be labeled as such. The calibration labels, which
are applied to instruments, have fields for the instrument serial number, calibration
date, calibration due date, and by whom. A good source of inexpensive calibration
labels is United Ad Label at 1-800-992-5755.
Accuracy
Ratios
Can you use a ruler to calibrate your digital calipers? Of course not! Wherever
possible calibration standards require an accuracy ratio of at least four to one. In
other words, the insturment being used to measure the calibrated instrument must be
at least four times as accurate as the calibrated instrument.
