The GMS1150 counter unit is a microprocessor-based unit, which can be operated as a stand-alone instrument in addition to being controlled and the settings adjusted via the PC. The settings are retained in non-volatile memory in the counter unit and are restored each time the power is applied to the instrument. When operated using PC software, all measurements and configuration changes are recorded in a text-based data file.

In its thickness gauge mode, the thickness of membranes etc are checked using a radioactive source and a GM detector mounted in a test jig. The membrane to be tested is placed between the radioactive source and the GM detector. The counts detected within the defined interval provide a measure of the thickness of the membrane. The counter will compare the count value recorded against user-defined minimum and maximum threshold values and provide a pass indication if the measured count fall within the allowed range, or provide a fail indication if the measured count is above or below the allowed range.

The adjustable detector HT voltage enables the gamma unit to be used with various types of GM tube. The correct operating voltage for a particular type of GM tube can be obtained from the GM tube manufacturer's data or by performing a plateau test using the PC software. The detector operating voltage would typically be set at the middle of the normal operating range as determined from the tube data or plateau test.

• Adjustable HT supply, 0-2000V
• GM Tube interface circuit and connector (SHV)
• Serial interface for adjusting settings via a PC (9-pin D plug)
• Low voltage power connector
• Perform a detector plateau test.