The Rad*Scanner Model 500 is easy to operate and almost maintenance free. All the switches are mounted on the top panel. The Rad*Scanner Model 500 battery power OFF/ON switch is located to the right when viewed facing the front label.  The Model 500 can be left on for two months or more with a fresh 9 volt alkaline battery installed.   The green light emitting diode (LED) flashes on for a moment at power up time if the battery voltage is adequate.  The THRESHOLD, CPM---uR/HR, SOUND ON and UPDATE---TOTAL switches are located on the left side of the top panel.

When the THRESHOLD switch is set toward the front label the Model 500 gives individual clicks for each particle detected.  The red LED flashes with each individual nuclear particle detected when the THRESHOLD switch is set in the individual click position. This is the Pulse mode. When the THRESHOLD switch is set toward the back side of the case, the Model 500 give a continuous tone sound when the average number of nuclear particles exceeds 1095 counts per minute ( 10 uGy/HR or 1.0 mR/HR rate). This corresponds to the Nuclear Regulatory Commission's suggested MAXIMUM SAFE WORKING LEVEL. This is the Threshold mode. Bursts of random background radiation will occasionally trigger a brief tone while in the Threshold mode.  Special threshold settings can be requested from the factory.
The CPM---uR/HR switch provides a choice between two useful scales of measurement. Moving the second switch toward the front label to the CPM (counts per minute) position records and displays the number of particles detected each minute. The display updates each minute and shows the previous minute's number of counts.  In the uR/HR position, away from the front label, the counter shows the rate of radiation flux in uR/HR (microRad/hour). The detector tube used in the Model 500 will indicate 1000 counts in each timing interval of 54.8 seconds when exposed to a gamma radiation field of 1000 uR/HR. This is the equivalent to a gamma field of 1.0 mR/HR or 10 uGy/HR. This is a convenient scale when comparing background radiation levels.

The SOUND ON switch allows individual clicks and the threshold tone to be turned on and off.  Setting the switch away from the front label allows the tone to be heard.   The red LED continues to flash when SOUND ON is in either position.

The UPDATE---TOTAL switch changes the liquid crystal display (LCD) counter operating mode. In the UPDATE position, toward the front label, the LCD is changed each timing interval to display the count collected in the previous time interval. In the TOTAL position the counter continues to collect and display each count as it occurs. In this mode, the number of counts over a longer time period can be collected and displayed. An hour, a day or more of accumulated exposure can be counted this way.  Turning the Model 500 off or switching the UPDATE---TOTAL switch back and forth will reset the counter. In the TOTAL mode, divide the total shown by the number of minutes elapsed to calculate the average count per minute, where an average of 1095 cpm = 10 uGy/hr = 1mR/hr.

You can determine the background count level in your surroundings by taking the a number of CPM (or uR/HR) readings and calculating the average value. Keep the Model 500 away from the ground and items and structures made of stone or concrete while determining the background level.  If the measurements are made outdoors in the open air and at sea level, you can expect a background count of 12 to 16 counts per minute.  At an altitude a mile above sea level the Rad*Scanner should indicate about twice that average count.  During times when our sun is experiencing solar flares or "magnetic storms" the background level will increase by several counts averaged over several hours.

The recommended battery replacement is once every two months if used constantly. Please OBSERVE BATTERY POLARITY. The Rad*Scanner Model 500 will not function properly with the battery reversed. Clean the outside of the device with a mild detergent solution on a damp, soft cloth. Do not immerse in water or saturate with liquids, to prevent damage to electronic components. Please remove battery if the Rad*Scanner is stored for a long period of time. REMEMBER: DO NOT TOUCH TUBE WINDOW.

The RadScanner Model 500VBR features a silent vibrating alarm, to alert you in high noise areas.