So who would want such an unusual device? Well, it’s a very long list, and includes just about anyone who wants to be able to keep an eye on their exposure to natural and man-made ionising radiation and, more importantly, be alerted when it rises above normal background levels. It will also be of particular interest to those who may come into contact with radioactive materials and radiation, working in hospital X-Ray and radiological medicine departments, undergoing radiotherapy, emergency and security personnel, the military, first responders and not forgetting people employed in the nuclear industry. You can also add airline pilots and frequent flyers that are exposed to higher than normal levels of cosmic radiation. Then there are geologists, mineralogists, miners, antique dealers and collectors, watch repairers and so on… We could go on, but let’s take a closer look at what it does.
It tells the time, of course, and the Gamma Master II has two clock displays: an accurate Swiss made, quartz-controlled analogue movement with luminous sweep second hand, and a secondary LCD display, showing hours, minutes, seconds, day, month and year, plus it has a daily alarm function. An electroluminescent backlight panel illuminates the display so it can be read at night and the tough but stylish stainless steel case is water-resistant and rated for depths of up to 100 metres (328 feet). Now for the really interesting stuff.
This unique watch contains a gamma-sensitive Geiger Müller tube radiation detector and monitoring circuitry designed to measure Dose Equivalent Rate (DER) and Dose Equivalent (DE), with programmable alarms to alert the wearer if the levels exceed a preset threshold. Dose Equivalent is a measure of radiation absorption by biological tissue, and an indication of potential health effects. This is expressed in internationally recognised standard units known as Sieverts. DER is a measure of DE in relation to time and the display on the Gamma Master II is constantly updated and shown in microsieverts per hour (µSv/hr). In addition, the Gamma Master II has a DER recording facility and it can store up to 500 readings, along with time and date, which can be uploaded* to a Windows PC** and displayed, graphed and recorded, along with readings from other Gamma Masters, using supplied software. The Gamma Master II’s DE reading, in millisieverts (mSv) gives the wearer a long-term indication of dose accumulation (1 – 9999 hours) and again there is a threshold alarm that sounds an audible bleep if DE exceeds a preset threshold.
To round off the key features, Gamma Master II has analogue
bargraph indicators showing approximate percentage of DE and DER in relation to
thresholds, a low battery indicator, full function reset button, switchable
alarm mute. It is fitted with a high quality leather strap and it comes in its
own heavily lacquered presentation case* with instructions, CD-ROM and calibration
certificate (* please be aware that as this has been used for photography, the case shows a bit of wear in places - nothing major - just a few little scratches and marks)
Time to get technical:
- Energy Range 0.066 – 1.5MeV
- Detector Type Geiger Müller tube
- DER Indication & Threshold range 0.01 to 9999.99 µSv/hr
- DER Indication Accuracy +/- 20 %
- DER Memory 500 records
- DE Indication & Threshold Range 0.01 to 9999.99 mSv
- DE Indication Accuracy +/- 20 %
- Accumulation range 1 – 9999 hours
- Alarm types Audible & visual
- Battery type 1 x CR2032 (supplied)
- Weight 210g
- Approximate Dimensions Dial dia 32mm, case dia 45mm, case thickness 18mm
* The PC requires an infrared (IrDa) receiver or plug-in IrDA adaptor (not supplied).
** Windows 92/2K/XP/W7/W8/W10
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Gamma Master II Wristwatch Personal Radiation Dosimeter
- Product Code: Gamma Master II Wristwatch Dosimeter
- Availability: In Stock