Tritium Illumination

Tell the time all the time

Being able to tell the time with ease in the dark is often overlooked in the process of buying a watch.

This ability however, of always being able to tell the time no matter what the conditions, is always highly valued in the day to day life of a watch.

This is the reason therefore why each and every Nite watch is fitted with tritium illumination - the very best form of watch illumination available.

Key Features

  • Tritium illumination is a completely safe and reliable form of illumination – the electron emitted by Tritium is so low in energy that it is unable to penetrate the human skin.

  • The Tritium illumination used in all Nite watches is supplied by mb-microtec of Switzerland – the original founders and market leaders of the technology.

  • The T rating relates to the total watch radiation content measured in millicuries. We offer both T25 and T100 rated watches.

  • Tritium illumination will provide a constant glow throughout the night unlike traditional illumination such as Superluminova which will fade in a number of hours.

  • Tritium illumination will provide a constant glow throughout the night unlike traditional illumination such as Superluminova which will fade in a number of hours.

  • Tritium illumination is completely self-powered and doesn’t require sunlight or any other form of external power to operate.


Tritium, also known as super heavy hydrogen, was first discovered by Ernest Rutherford, ML Oliphant and Paul Harteckin in 1934.

Tritium emits electrons through beta decay and when these electrons interact with a phosphorous material, a fluorescent light is created that can last up to 20 years.

When this Tritium powered illumination is sealed inside a glass tube, it is known as a GTLS (Gaseous Tritium Light Source) which is up to 100 timesbrighter over a long period than any comparable technology.

To produce a GTLS vial, glass is lined with phosphorescent material, then filled and pressurised by a machine with gaseous tritium and sliced into segments by a laser beam to be sealed hermetically.

Inside the vial, the electrons emitted by the tritium gas excites the phosphor to give off the cold continuous light. GTLS can be created in different colours, generally green is perceived by the human eye as the brightest colour.

Completely self-powered and providing a constant glow throughout the night, Tritium illumination technology has been trusted for decades by the emergency services, mountaineers, deep-sea divers and military personnel due to its unwavering reliability and performance in mission critical situations.

T25 VS T100

We offer both T25 and T100 rated Tritium watches. The T rating refers to the total watch radiation content which is measured in millicuries. All watches with a T25 rating contain up to 25mCi of radiation content and similarly, watches with a T100 rating contain above 25mCi and up to 100mCi. Whilst there are differences between the amount of mCi in the T25 and T100 models, the idea of “which is better” is simply a choice of preference and taste.


I enjoyed sifting through the website on making my choice on the right look - for me. My watch arrived within 2 days and within the scheduled time gap.It was well packaged.I immediately checked out the luminosity by sticking the watch under my duvet an enclosing my head in the dark.The luminous properties of the watch are outstanding. Mine is blue with the orange at 12.00. I am very happy with my purchase and this wrist watch with the blue composite strap and blue face looks very smart. I bought the model with this strap as I have problems with my wrist occasionally swelling and the fixed dimensions of the stainless steel bracelet would not suit me. Very reasonable cost for a watch which meets my requirements!

Gavin Steel 15/7/19

I took delivery of my watch last Thursday and I am delighted with my purchase. I bought the Hawk T100 as I have wanted one for a while. Thank you the Nite watches team for first class service. I will be purchasing again and did I say I am loving my watch superb looking timepiece... ... oh I did 😁. Thanks again and highly recommend Nite watches.

Sandi Shearer 15/7/19

Excellent service and backup icon watch has not lost or gained a second in the month since l got it. Very pleased looks good and works as advertised.

Stewart Murcutt 14/7/19

Arrived fast, match needed And Nite Watch is very durable.

viroj soontornvivat 12/7/19

Purchased a watch strap for my hawk watch, arrived promptly very pleased with the service received

Matt Ellingham 10/7/19

An excellent watch

Mr WALLACE Wallace McDonald 9/7/19

Excellent service, easy to order my new strap which was dispatched super quick. Had a problem sourceing a broken fastening pin, but one call got a replacement on route.

Geoff Cooper 9/7/19

I absolutely love the Alpha range of watches. They are extremely well built, very comfortable to wear and offer all round excellent value for money. The quality, detailing and finish are second to none. I have both the green and blue lume versions of this model. The green is a little brighter than the blue, but if anyone is considering the blue version you won’t be disappointed in my opinion as it is still extremely legible in dark conditions (as well as looking great). Also, the customer service has been exceptional every time I’ve dealt with the company. Highly recommended.

Richard 8/7/19

I bought the Nite Alpha watch about a year ago and it’s a great watch very sturdy however I found that with a shirt on the watch is too big to fit comfortably under the cuff so have bought the marquis which is much thinner and more of a dress watch .

colin bateman 7/7/19

I love my Hawk watch. Its rugged distinctive and most importantly great to use in the dark. Only problem is the PVD straps only last about a year and break in the same place every time. So I have now changed it to a webbing strap. Which was delivered quickly and will hopefully last longer.

Richard Cairns 7/7/19

Quick, efficient service

Andy C 4/7/19

Brilliant service provided - my watch arrived within a couple of days.

Norman 4/7/19

ICON PVD Easy to order and fast delivery as well. A well put together piece which the pictures do not do justice to.The dial is very legible in all light and the hands and markers really bright in the dark everything lines up nicely too.The leather strap is fairly chunky but comfortable The 715iL gives 10 years of power. Ideal.

Richie 3/7/19

Outstanding watch better than outstanding Lume

Joseph Oxentenko 2/7/19

Very impressive service with really good payment options from klarna . The Marqess watch is superb in every way.

Michael 2/7/19

Fook transparency of my order and a really fast delivery.

Sergej Neifach 1/7/19

Excellent product with great service

Michael 29/6/19

I ordered my NITE watch around 5:00pm EST on a Thursday and it arrived in Florida by early Monday afternoon!

Stephen Johnson 28/6/19

Great watch, great quality,


I really like the range and have bought several different models from Nite Watches over the past few years always very pleased with both the service and prompt delivery.

Ronan Clarke 27/6/19

Now you know all about Tritium illumination

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