How do I troubleshoot noisy scans?

The noise level on the scans depends on several factors like measurement mode and time, the detector type selected, the energy and dose rate, and the pulse repetition frequency. Also, Depending on the environmental and measurement conditions, a continuous scan always shows some kind of noise by design, whereby a step by step measured scan will be much smoother.

With all the reasons listed above here are the steps to troubleshoot the root of the noise.

Step 1

Dust or Humidity inside connectors - check against another for testing if it is the case take an air canister and spray both connectors CCU and chamber.

Step 2

Detector in bad condition(humidity, dust, mechanical defect) - reach out to IBA support for further assistance.

Step 3

Reference detector is not in the field (especially when the field size becomes smaller than during phantom setup).

Step 4

Reference diode is in field with wrong orientation. The white dot at tip must be towards to the focus.

Step 5

High voltage is not switched-on or to low (if ionization chambers used), check the electrometer setup in myQA Accept.

Step 6

The selected sensitivity range for the used detector is not sufficient. Please make sure the electrometer is setup properly in myQA Accept.

Step 7

The Ratio ( reference division) is not activate. Please review the electrometer setup in myQA Accept.

Step 8

The sampling/measuring time is too short, especially in step mode scans. Please review the measurement queue setup in myQA accept.

Step 9

Scanning speed is too high in the case of continuous mode or the servos are creating too many waves at the water surface. Please revise measurement queue setup in myQA Accept.

Step 10

The detector extension cable is too long or have different length. the recommended cable length is 5m.