QUICK START GUIDE FOR GIS-4

General: This unit is not calibrated and appears to have a longer than normal dead time. It will give usable relative readings on Total count (TC) and K+U+Th but the other ranges should not be trusted. Don't change the calibration knob, it won't help you and may in fact make things worse.

There is a full manual in the box if you need a more thorough explanation.

The most sensitive spot is around the head under or beside the meter. The orange dot is about the centre of the crystal.

1.	Turn it on to TC or K+U+Th using the FUNCTION knob - The speaker will start squealing. press the white reset button to stop it.

2.	Check your battery level by holding the BAT TEST/RESET button down for 3 seconds. If you have a number > 1000 you are OK. Do not operate the instrument with a battery level below 1000 as this may permanently damage the display. If you need to replace the batteries they are under the handle pivot point. Just undo the 3 bolts.

3.	Leave the count rate on 1 SEC as the other integration times appear to give erratic results.

4.	Place the meter against the material you want to analyse and compare the count rate with background.

The meter takes about 15m to warm up and stabilise so although you will get reasonable relative readings when you first switch it on the repeatability will improve as it warms up.

To give you some idea of relative levels the table shows the differences between background and a weak uranium source in the office.

TC	K+U+Th	U+Th	Th
Background	200	3	3	0
US-2 source under meter	1000	50	30	0