FAQ

Questions and answers regarding the Comecer Calibration Centre services, from the request for calibration to the use of the certificate issued.

• What can be calibrated
• When to calibrate
• Using the calibration certificate

If the answer you are looking for is not among the following, write to the Comecer Calibration Centre, filling-in the contact module.

What can be calibrated

What type of instruments do you calibrate?

The Comecer Calibration Centre performs calibration of personal passive dosimeters and measurement assemblies (instruments) of ionising radiation in the radioprotection ambit, quality controls and measurement of activity. (see Instruments section).

Does the Comecer Calibration Centre modify and/or repair the instruments undergoing calibration?

No, the Calibration Centre does not perform revisions or repairs on the instruments, but supplies the calibration factor that indicates the relation between the reference values and the values measured by the instrument.

Must I calibrate the instrument for the first time: what do I have to do?

First request an estimate for calibration. If you accept our offer you can send or personally deliver the instrument to the Comecer Calibration Centre.

With which type of sources/beams is it possible to perform calibration?

The Table of reference contains all types of beams and sources that can be used for calibration in the Comecer Centre.

Do we have to calibrate an instrument that we use to check the presence of radioactivity in materials, can this be performed at your establishment?

Certainly, instruments that measure the quantity of radioactivity can be calibrated at our Centre.

Do you calibrate instruments used to measure surface contamination?

Yes, the Calibration Centre has many sources that can be used to calibrate contamination meters.

Do you calibrate Dose calibrators?

Yes, the Calibration Centre has liquid sources that can be used to calibrate dose calibrators.

Do quality controls and guidelines to be performed on anti -x-ray lead aprons exist?

As of today the materials used for protection from radiation must be in compliance with the IEC EN 61331 Standard. This Standard explains the methods of execution of the measurements for the determination of the equivalent in lead.

The controls that can be performed (usually by the Qualified Expert), are the following:

• visual check of the state of the item (no breakage)
• checking the equivalent in lead, using for example (as envisioned by the Standard stated) a high voltage of 100 kV, filtration of 0.25 mm of Al to perform a dose abatement measurement comparing the results with a thickness of lead.

When to calibrate

What the criteria for establishing the frequency of calibration?

The frequency of calibration can be established by analysing the following parameters:

• Frequency of use
• Importance of the instrument
• Importance of the measurement
• Number of instruments owned that measure the same quantity: if two instruments are owned for the measurement of the same quantity, it is possible to alternate the calibration of the instruments every 2 years
• Any repairs performed on the instrument

Is their a Standard regarding the frequency of calibration?

Currently the ISO Standards envision that the user must decide the frequency of controls. In the past for portable instruments used in radioprotection, the UNI 8143 Standard (1980) envisioned that the calibration controls were performed at least once a year.

Using the calibration certificate

How is the Calibration factor used?

The Calibration factor must be multiplied by the value measured by the instrument: in this way the correct value of the detection is obtained.

What is the difference between the Calibration factor and the Dimensionless calibration factor?

The Calibration factor corrects the measurement and takes the value read by the instrument to the reference unit of measurement (mGy or mGy/h); the Dimensionless calibration factor corrects the measurement without modifying the unit of measurement of the instrument.

What are the error limits accepted for the issue of the certificate?

It is the use who must establish the limits of use of the instrument and for any repairs. The Calibration Centre reserves the right to inform the operator if the instrument is not in compliance with the specifications envisioned by the manufacturer or is unusable for the purposes envisioned.