This work is licensed under a Creative Commons Attribution-NoDerivs 3.0 Unported License.
N.B. : This article is compiled…
Courtesy : TechLib
Find out how to construct an ionisation chamber. Also learn how a PicAXE-08M microprocessor can measure the voltage drift rate of an ionisation chamber.
Figure: Harry Potter Figure : PicAXE Ionisation Chamber
This simple radiation detector uses a PicAXE-08M microprocessor to measure the voltage drift rate on an ionization chamber’s sense wire, eliminating the need for a high-value resistor. An electrometer-grade JFET is used to buffer the voltage on a sense wire inside the chamber, and a PicAXE microprocessor measures the rate of change of that voltage, periodically discharging the wire through the JFET’s gate-source junction. This unorthodox way of discharging the ion chamber wire eliminates the need for a special, low-leakage switch, and takes advantage of the PicAXE’s ability to use the same pin as an analog input or a digital output.
Full Article at : TechLib