# Latitude Professional Gammamaster



## ron (Dec 12, 2003)

Iâ€™ve been promising for a while now to post details of my Geiger Counter Watch....so here it is!


















The watch is a Latitude Professional Gammamaster â€" as itâ€™s name suggests, the watch contains an inbuilt Geiger counter. Latitude are a Hong Kong based watch manufacturer, specialising in high-end technical digital watches.

The diameter of the crystal is 3 cm, and the height of the watch is 2 cm

Itâ€™s quite a heavy watch, weighing in at 170g with the stainless steel bracelet (without, it weighs 95g). It also comes with a lighter black rubber strap.

Looking at the face â€" you can see it is divided into three main LCD displays.

The LCD display at the bottom left is showing 00.19 currently â€" this is the current background radiation level when I took the picture. The units are ÂµSv/h â€" or micro Sieverts per hour. The Sievert is a measure of dose rate â€" similar to REMs. The average yearly exposure at ground level is about 1 mSv of gamma radiation per year.

A typical "normal" background reading would be between 0.05 to 0.3 ÂµSv/h â€" so 0.19 shown in the picture is quite safe (phew!)

How to test the watch?

Answer: Just wear it next time you fly somewhere â€" at 30,000ft, you are exposed to approximately 10x ground level background radiation â€" and the watch shows this. You can see the background counter increasing in line with the planeâ€™s altitude! I have tried this myself â€" it is amazing to watch (excuse the pun)

The curved LCD display between 10-2 is a graphical representation of the current rate. I have set this to 0.4ÂµSv/h â€" and you can see the 'blocks' stop just short of the half way mark (under the 12 marker). This just shows that 0.19/0.4 is just under half way. An alarm would sound if the background hit 0.4ÂµSv/h (for my particular settings)

The watch can also be set to beep each time an individual gamma ray is detected.

Here are the key numbers â€" to keep in mind when looking at the dose rate displayâ€¦..

0.1-0.3ÂµSv/h : normal background

3ÂµSv/h : flight on plane

10ÂµSv/h : near a radium dial watch









100ÂµSv/h : standing by the side of a truck carrying radioactive material









1000ÂµSv/h : near high grade uranium ore
















2000+ : exposed artificial source









The watch has been *compared with readings from a full sized radiation detection device* (a Victoreen Scintillation Counter Model 190/429) and stayed within 5% of the readings given by the Victoreen Instrument. Amazing that something you wear on your wrist can be that accurate.

The circular LCD panel at 9 o'clock represents the cumulative yearly dose. This is user definable. As can be seen, Iâ€™m quite low (started the 'clock' in October last year)

The dose rate display can also display a regular LCD time display. An interesting fact about this is that this LCD time display can be regulated! The LCD time is factory set to run fast (about half a minute per week). The procedure for regulating this is to set the time exactly using a reliable source (ie one of my radio controlled watches), then let it run for a whole week, noting at the end how far adrift the time is. When I did this, I was running 32 seconds fast. All you do then is key â€œ32â€ into another adjustment screen, and this resets the timing by 32 seconds per week. After doing this, the watch has remained accurate *to the second *for over two months.!

Apparently this is possible due to the fact that the digital part of the watch is an oscillator on a microprocessor. The adjustment does NOT change the frequency of the oscillation, but tells the microprocessor to use 99999 (or whatever) oscillations and call it a second, rather than 100000 â€" in other words itâ€™s a software adjustment.

The analogue watch is also extremely accurate. Itâ€™s driven by a Ronda 763 quartz movement â€" which according to Roy is a "very good movement". Itâ€™s accuracy certainly bears that out 100%. The post where I asked about this can be seen *here*

I found out just recently that my Gammamaster is not apparently the first Geiger counter watch madeâ€¦â€¦.apparently, such a watch was manufactured back in 1993 â€" specifically the 'Gamma Control' watch. This was developed by Ernst Uhlmann and was sold by Yperwatch of Thurgau, Germany.

An amazing watch - one I have no regrets buying, and one I will never sell


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## JoT (Aug 12, 2003)

Fantastic post Ron ... I am going to get one for next time I go to Ukraine


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## pg tips (May 16, 2003)

Very interesting that Ron.

And bloody good pics as well, nice one. I take it you like the Samsung then!


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## ron (Dec 12, 2003)

Hello PG



> I take it you like the Samsung then!


Too right!









Check out my post in the Sales forum - used it for that too


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## Silver Hawk (Dec 2, 2003)

Hi Ron,

Great post...so what does a watch like this cost? Are we talking hundreds or thousands?

(I used to work in research labs carrying out weekly radioimmunoassays; I would have loved one of these watches then...)

Paul


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## Mrcrowley (Apr 23, 2003)

Fantastic Ron, though maybe a bit scary at times?

In an environment, & radiation level jumps. I would run(or wheel) out fast!

What's the Samsung thing? Have I missed something?


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## Nalu (Nov 28, 2003)

Well done, Ron. Love the photos and you've done a great job on the description.

One question: where is the sensor? As I recall from my undergraduate nuke engineering and physics days, the sensor tube on a Geiger counter is fragile - yet this watch is good to 10ATM?. Hard to believe something new might have developed in the last 20 years...









I'd love to get my hands on one of these tools! I get exposed to ionizing radiation on a regular basis and would appreciate the chance to monitor my exposure rate on my own. It might even get the RLT4 off my wrist - at work anyway. Is it still available?


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## Nalu (Nov 28, 2003)

OK,

I've answered some of my questions. The watch is available at: Gammawatch.com

Online price is 485USD, shipping included.

While the site does a good job of informing the reader of watch particulars, it does not address the sensor issue. Some things shall remain a mystery - "pay no attention to the man behind the curtain!"


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## ron (Dec 12, 2003)

Hello Mr C



> What's the Samsung thing? Have I missed something?


PG was referring to my new Samsung Digimax V4 digital camera









All is explained *here* in the Photography Forum

I needed to get my own digital, and after much (excellent) advice from the forum, finally decided to go for the same camera as PG!

Got it last week, and the Gammamaster pics are my first shots posted taken with it.


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## Griff (Feb 23, 2003)

JoT said:


> Fantastic post Ron ... I am going to get one for next time I go to Ukraine


You might want to wear one around Seascale too. Might be interesting in Norway and Sweden also after Chernobyl!!!


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## Stan (Aug 7, 2003)

Nicely done Ron.









The Samsung seems to be doing the job.................... with some skillful use.


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## ron (Dec 12, 2003)

Thanks Stan!

I'm very pleased with the camera - and these pictures - especially as I just stuck the camera on "easy" mode and pressed the shutter! I did have it on a tripod though, which probably helped.

Next is to experiment more with all the settings - and also lighting. I tried some shots with the watch under a 'dome' (aka the top white bit of an IKEA lamp!) - but they weren't too good. I'm sure this was due to my setup (not enough illumination outside etc). So many things to test out now....!

Now I need to find another interesting watch to post









Decisions, decisions

Maybe my gold 1967 Tudor manual wind - I think I've posted it already when I first joined the forum - but now I can take much better shots. That may be a nice one to do next......


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## Stan (Aug 7, 2003)

Go for it Ron, let's see some more watches...... please.


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## MIKE (Feb 23, 2003)

Stan said:


> Go for it Ron, let's see some more watches...... please.


Hi Ron,

Yes go for it, I'm all ways intrested in seeing photo's of what other members collect.

MIKE..

P.S

Great pictures!!


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## ron (Dec 12, 2003)

Thanks for your comments Stan and Mike

I'll put the camera through it's paces this weekend

I want to try some 'natural light' shots - which is not possible during the week as I'm stuck at work in daylight hours! I think I read somewhere on some thread that Roy's pictures are taken in natural light (by a window?) - and I think they all look great.

Watch this space (well, watch for a new thread!)


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## odklizec (May 19, 2004)

Hi Ron,

Nice review and watch! Could you, please, post some more pics of this watch (mainly with watch on hand and some "size" comparative images)? What is your experience with this watch after few months? Isn't the thickness around 2cm a major handicap?


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## pg tips (May 16, 2003)

welcome to the forum odklizec

Nice to see new members reviving old threads, goes to show our past posts are being read all the time.


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## Nalu (Nov 28, 2003)

I'll try to post some pics next week. While it is a tall watch, it's compact at 40mm diameter (excluding pushers). I don't wear mine for looks or sheer gadget-ness, but I do wear it regularly during the work day to try to get a better handle on my exposure levels. Unfortunately I catch most of my exposure to ionizing radiation while in cases when I can't wear a watch.


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## gravedodger (Feb 15, 2004)

I'm guessin' that Tritium coated numerals and hands would mess this baby up


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## odklizec (May 19, 2004)

*To pg tips...*

Thanks for welcoming me! In fact, I have searched for more information about this watch on Google and Roy's Gammamaster review was one of the returned links







This is how I found this great watch-lovers forum.

*To Nalu...*

Thank you in advance. In fact, I would like to buy this watch, because I'm very interesting about the background radiation values here in Czech/Slovak Republic, where I live. Both countries were affected (mainly the northern borders) by Chernobyl disaster and I'm almost sure we still don't know the truth







There are also two nuclear power plants and few closed uranium mines. I don't expect miracles from that small "Geiger", but it may be useful for my trips around both countries.


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