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Quartz Control Plate (QCP) FAQ: Calibration, Use, Handling, and Certification
Learn what a Quartz Control Plate (QCP) is, how it is used, how calibration works, what the certificate means, and how to handle and store a QCP properly.
What is a Quartz Control Plate (QCP)?
A Quartz Control Plate (QCP) is a certified reference material used to verify the optical rotation performance of polarimeters and saccharimeters.
What is a QCP used for?
A QCP is used for:
- Verification of optical rotation performance
- Evaluation of instrument linearity
- Support of performance verification and calibration-related activities
Is a QCP used to verify temperature accuracy?
No. A QCP is not intended to verify or calibrate the temperature accuracy of a polarimeter. It is used to verify optical rotation performance.
Is the quartz physically adjusted during calibration?
No. The quartz is not physically adjusted during calibration. The certified values represent its condition at the time of calibration and confirm that it met specifications at that time.
Can handling affect QCP performance?
Yes. Physical damage, including scratches, stress, or impact, may affect QCP measurement performance and may result in failure to meet certification criteria.
How should a QCP be handled?
To help maintain performance:
- Handle the QCP by the mount or assembly
- Avoid contact with optical surfaces
- Protect it from mechanical shock, contamination, and chemical exposure
- Minimize handling
- Allow the QCP to stabilize to ambient conditions prior to measurement
How should a QCP be stored?
Store the QCP in the supplied protective container when it is not in use.
What does recalibration of a QCP include?
Recalibration consists of measurement and certification of the quartz. The QCP is not physically adjusted or altered during this process.
Is the calibration date the same as an expiration date?
No. The calibration date indicates when the QCP was calibrated. It is not an expiration date.
Does a QCP expire?
A QCP is an artifact reference material. Its continued suitability depends on its physical condition, handling, and use.
How often should a QCP be recalibrated?
A typical recalibration interval is 2 to 3 years, depending on the application and frequency of use. Recalibration intervals should be evaluated in accordance with the user’s internal procedures.
Who is responsible for establishing recalibration intervals?
The user is responsible for establishing appropriate recalibration intervals based on internal procedures, regulatory requirements, and risk considerations.
For a new QCP, should the recalibration interval be based on the calibration date or the first use date?
For newly placed QCPs into service, recalibration intervals may be established based on the date the QCP is first placed into use, rather than the calibration date, in accordance with the user’s internal procedures.
Where is QCP recalibration performed?
Recalibration is performed at the Rudolph Research Analytical factory.
Can Rudolph recalibrate non-Rudolph QCPs?
No. Non-Rudolph QCPs are not recalibrated by Rudolph. Trade-in options may be available.
How do I know if my QCP meets specifications?
The issuance of a Calibration Certificate indicates that the QCP met all applicable certification criteria at the time of calibration.
If a QCP does not meet certification criteria, a certificate is not issued and the customer is notified with supporting information.
What do the values on the Calibration Certificate represent?
The certificate reports certified optical rotation values at specified wavelengths, along with associated measurement uncertainty. These values are used for comparison with instrument readings as part of performance verification.
Why are “as-found” and “as-left” values not reported?
The QCP is not adjusted during calibration. Because no physical changes are made, the certified values represent its condition at the time of calibration. Separate “as-found” and “as-left” values are not reported.
What happens if a QCP does not meet certification criteria?
If a QCP does not meet certification criteria:
- A Calibration Certificate is not issued
- The customer is notified with supporting information
- Options such as replacement may be available
How can we further assist you?
Give us a call, we are happy to help! (973) 584-1558 Monday - Friday 8:30AM - 5PM EST Request a quote for a new or calibration of an existing QCP.