|
|
| Instrument Calibration |
The purpose of
instrument calibration is to provide a correlation between the response produced by an
instrument and the concentration of silica producing the response. (This correlation is
often referred to as calibration or standard curve.) In addition, the accuracy of the
calibration during the analysis of samples should be demonstrated. As a minimum, the
accuracy should be demonstrated at the beginning and end of each analytical run.
Since the concentration of the materials used to produce the calibration curve directly
effects the results of the sample analysis, these materials should be characterized as
well as possible. Possible sources of calibration materials, in order of preference, are:
- National Institute for Standards and Technology (NIST) or NIST traceable
- Other recognized standard reference material
- Well characterized material from a recognized source
- Proficiency testing materials
- High purity materials from a commercial supplier
- Materials from other known sources
- Materials from unknown sources
Since instrument calibration can change over time, the frequency of calibration and
calibration verifications is important.
|
|
Back to Top 
www.osha.gov
