Usefull information

Dosimetry from A to Z

In the following table you will find detailed explanations of the codifications that in the past were imprinted on the results report. This information is also available in abbreviated form on the back of our letterhead which we use for the results report, the delivery notes and the order, assignment and modification sheets.

All explanatory notes are given in plain text in the current statement of results.

CommentExplanatory noteEffect on the personal dose valueRecommended measures
Dose value without further comment. The dosimeter was frontally exposed to radiation, according to its intended operation purpose.Dose value is correct within the admissible error tolerances.Check out whether the verification thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose.
The dosimeter has been partially covered. The dosimeter was either covered by an object that has influenced the blackening of the film, or it was not evenly illuminated during irradiation. Evaluation of the dosimeter can be carried out either only to a limited extent or not at all.The specified dose value may lie outside the admissible error tolerances.Check out whether the verification thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose. Consider possibility of exceeding the error tolerances.
The dosimeter has not been irradiated with normal (0°) incidence of radiation. The dosimeter was exposed to an angular radiation source. At a higher angle of radiation than 60°, the dosimeter can be evaluated either only to a limited extent or not at all.The dose may be underestimated if angle is near 90°.

Check out whether the verification thresholds or the dose limit are exceeded and, if necessary, calculate the effective dose. Consider possibility of exceeding the error tolerances.

Check out whether the wearing location of the dosimeter is consistent with the present conditions of exposure. 
Back of the dosimeter has been exposed to radiation. 

The side of the dosimeter marked as BACK was exposed to radiation.

a) If it cannot be excluded that the radiation registered on the dosimeter has passed through the body of the dosimeter wearer, the competent authority will be notified.

b) If the dosimeter was only worn the wrong way, it can be detected in most cases by means of the filter image on the developed film. In this case, no notification to the competent authority will be made.

Dose value is correct within the permissible error tolerances.

a) Once the radiation passed through the body of the wearer onto the dosimeter, the measured personal dose does not constitute a conservative estimate for the effective dose.

b) Since the dosimeter's front and back are equipped with an identical filter assembly, the calculated dose value is correct even in case of backward radiation.

a) In case of backward radiation, an estimation of the body dose should always be made. If the individual dose values lie below the verification threshold, the conversion factors can be used for estimation.

b) Check out whether the verification thresholds or the dose limit are exceeded and, if necessary, calculate the effective dose. Instruct the wearer on the proper wearing of the dosimeter. 
Unmoved dosimeter has been exposed to direct radiation. The dosimeter was kept unmoved in a direct radiation beam instead of being worn by a person during work.The detected dose value does not reflect an individual dose.A replacement dose must be determined.
The dosimeter cannot be evaluated. The dosimeter cannot be evaluated because either the detector is damaged, or the detected contamination is too extensive, the dosimeter cover is too large, or the inclination of the angular radiation is too high.No dose value can be evaluated.A replacement dose must be determined.
The film has been exposed to radiation outside the badge. The film has been exposed to radiation outside the badge. Due to the lack of filter image on the film, the worst case of exposure to very hard gamma radiation is automatically determined through the evaluation. The detected dose value does not reflect an individual dose but gives the most conservative dose that can be evaluated.A replacement dose must be determined. 
Suspicion of measuring range exceedance. The dosimeter cannot be evaluated because either the dose is too high, so that the detector has reached oversaturation, or the measuring film has been completely blackened by light.No dose value can be evaluated.A replacement dose must be determined.
Rapid evaluation.Special evaluation that takes place immediately upon the arrival of the dosimeter at the AWST (the monitoring service). Dose value is correct within the permissible error tolerances.Check out whether the verification  thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose.
Late return of dosimeters.

The dosimeter was not returned within the specified deadline.

For the evaluation of film badge dosimeters, specially prepared calibration curves are necessary. Routinely, all dosimeters, which are not received within the specified deadline, are evaluated using the calibration curves of the previous monitoring period. Consideration of the natural background radiation is more difficult.
Typically, only dosimeters issued in the past 7 months are evaluated.
The specified dose value may lie outside the permissible error tolerances.

Returning dosimeters after expiration of the specified deadline, should be avoided.

Check out whether the verification  thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose. Consider possibility of exceeding the error tolerances.
The dosimeter is radioactively contaminated.

The dose measurement film shows an autoradiogram (blackening pattern), which, on proper handling of the film, is an indication of a radioactive contamination of the dosimeter.

If the contaminated area is too large, the evaluation of the dosimeter can be carried out either only to a limited extent or not at all.

If not specified in the monitoring sheet that the dosimeter wearer worked with unsealed radioactive materials, an immediate notification is sent to the competent authority.
The specified dose value may lie outside the permissible error tolerances.

Check out whether the verification  thresholds or the limit values are exceeded and, if necessary, calculate the body dose.

If the badge has been contaminated with long-lived radionuclides, clean it or renew it. 
The film cannot be evaluated - exposure to light.The measurement film arrived in a damaged packaging, so that light is the cause of the film blackening.No dose value can be evaluated.A replacement dose must be determined.
Processing error at the AWST ( the monitoring service).Due to an operational failure at the AWST (the monitoring service), no evaluation can be carried out for the dosimeter.No dose value can be evaluated.A replacement dose must be determined.

The blister packaging is damaged – no evaluation

Damaged blister packaging makes the evaluation impossible. No dose value can be evaluated.A replacement dose must be determined.
Filter missing from the cassette.The autoradiogram indicates, that a filter is missing from the dosimeter badge. Evaluation is only possible to a limited extent.The specified dose value may lie outside the admissible error tolerances.

Check out whether the verification thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose.

Replace the cassette immediately. 
Dosimeter is damaged, but it can be evaluated. The TL-detector in the dosimeter is broken. Evaluation is only possible to a limited extent.The specified dose value may lie outside the permissible error tolerances.Check out whether the verification thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose.  
Special notification is to be made. 

According to the Directive on requirements for personal dose monitoring, official monitoring services are  obliged to notify immediately the competent authority  and the competent radiation protection officer in the following cases:

*Dose is higher than 6 mSv whole-body dose, or 150 mSv partial-body dose.

*Indication of radioactive contamination, if no handling of unsealed radioactive materials is specified.

*Person has been exposed to backward directed radiation, when the personal dose multiplied with the appropriate conversion factor is higher than 5 mSv.

Depending on the nature of the special notification, the circumstances of the radiation exposure, that led to this notification, have to be clarified. The AWST will assist you in answering any questions you may have.
Film cannot be evaluated - it is glued together.The film is glued together due to overheating, humidity or chemical influence. Evaluation is not possible. No dose value can be evaluated.A replacement dose must be determined.
Very old badge. No PTB type approval exists for this cassette, it can therefore no longer be used for official dosimetry.Since no proper calibration of this system exists, the specified dose value may lie outside the permissible error tolerances.The cassette should be replaced with an actual one. Apply for a replacement dose.
Automatic loss

No return of the dosimeter within the evaluation deadline. According to the guidelines, we are obliged to notify the supervisory authority and the radiation protection commissioner of the loss.

A replacement dose must be determined.
The film is not inserted properly. 

The dosimeter was frontally exposed to radiation, according to its intended operation purpose.

The film was inserted upside down in the badge, which makes the evaluation more difficult.
The dose value lies within the permissible error tolerances.Check out whether the verification thresholds or the dose limits are exceeded and, if necessary, calculate the effective dose.
Indication of the presence of a beta-ray source (and low energy electrons).The audioradiogram of the measurement film indicates the presence of a beta-ray source and low energy electrons.

The dose caused by the irradiation is not indicated. 
Notification of the supervisory authority is required. 

According to the Directive on requirements for personal dose monitoring, official monitoring services are obliged to notify immediately the competent authority and the competent radiation protection officer in the following cases:

* Dose is higher than 2 mSv whole-body dose, or 50 mSv partial-body dose.

*Due to improper handling of the dosimeter, no evaluation is possible.

*Indication of radioactive contamination, if no handling of unsealed radioactive materials is specified.

*Person has been exposed to backward directed radiation.

 

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