FAQ Service & Support

Start by filling out our Service Order Form. Here you mark/write what you want to send in to us. After that please contact our distributor for your country, they will guide you in your choice of calibrations, repairs and upgrades. This will result in a Calibration Order Form which tells us what you want us to do with your equipment.
If we don't have a distributor for your country, please contact us on: service@rti.se
When both these documents are filled in - the instrument is ready to send to us.

We have an average turn-around of two weeks.

We will always like to proivide quick and good service to you and to be able to do that we'll need to know what kind of instrument you have (type, serial number ...) and if you have the latest versions of software and/or firmware. Sometimes you can find answers to your problems in the manual or by checking that you have the latest versions of software and/or firmware.

Yes. Please mail us at: service@rti.se

Why the 1 point method is to prefer when measuring CTDI_w with the CT Dose Profiler

What's the difference?

Using the 1 point method only one exposure in the centre hole is performed for each CTDI_w estimation. This is possible by using know relations in the dose distribution between the centre hole and the 4 periphery holes. This relation is defined by the "k-factor".

How accurate is the k-factor?

The k-factors have been extracted from statistics during two or three years  from measurements of the CTDI_w and CTDI₁₀₀ measured with ion chambers on different scanners.

The variation between different scanners and bowtie filters are less than ±5%. This difference gives less distribution to the expanded uncertainty than influences by measuring the 5 periphery holes individually. Factors that add inaccuracy when measuring in the periphery holes are energy dependencies, low signal and high dynamic variation in signal during the tube rotation. When using the CT dose profiler in the periphery holes during a scan the pitch has to be less than 0,5 to avoid loss of information for the dose estimation.

Can I check the k-factor myself?

Yes; You can easily extract you k-factor for each of your CT scanners by using previous measurements with ion chambers.

RTI strongly recommends the 1 point method to be used for CTDI_w measurements with the CT Dose Profiler. The method saves time and gives a higher accuracy than the 5 point method, either using a pencil ion chamber or the CT Dose Profiler.

No, not yet.

If the camera is mounted on the tube housing, vibrations may cause a blurring of the image. If this happens, we recommend that you instead mount the camera to an object which is firmly attached to the floor.