As Rob at Toppers indicated in another thread he sent me a Engineer Hydrocarbon TMT Celsius graduated watch to evaluate and review. The Watch uses a Ball Caliber 9018 which is based on an ETA 2892-A2 with the mechanical temperature module added to it. The mechanical thermometer proposed challenges for Ball since it must fit in a 5.1mm area within the movement. Since it is an EHC it must meet all the other requirements. A patented regulating screws was developed to allow adjustability and reach the desired accuracy for the thermometer module.
So before we get into the other details on the watch let’s see how well it does. Now I’ll admit I do not have lab calibrated temperature measurement equipment. I do have an indoor/outdoor thermometer that based on average temperatures reads to within 2 degrees Fahrenheit. Since this is a Celsius watch I relied on the table on the case back of the watch for rough conversions and the conversion calculator located at Fahrenheit to Celsius Converter for final conversions. I also had for comparison sake a Casio G-Shock Atomic/Tough Solar Riseman. Since your not really going to test cold temperatures in South Florida very well with a low this year of 54 degrees F I had to come up with options. Best solution was a ski jacket thermometer for measurement from my military days(I did not always live in FL) and my garage refrigerator and freezer as my cold chamber.
Now the hot was no problem. Even this time of year on a sunny day I can see over 100degrees F on my back patio in direct sun. So this was the first test. As you can see from the thermometer we hit 101 degrees F in the afternoon sun. I allowed both the TMT and the Riseman to sit out in the sun for 1 hour off the wrist. The TMT reads around 39-40 degrees C at this point which converts to 102 - 104 degrees F. This is within the tolerance of our measurement device. The Riseman as you can see is reading 112 degrees F (I tried to switch to C mode and it read 44.4 C so it was consistent). I think the black case may make it run warmer. To prove this theory I tried a second measurement in the shade and the Ball had the same reading as the test thermometer and the Riseman was within +2 degrees F. So far, so good.
Now for the cold which started in the refrigerator which measured at 33degrees F. The Rise man read .6 high and the TMT about the same amount low so I would have to say it is a tie. I will note that the Sapphire crystal fogs in a few seconds in the 81 degree F Florida day air when I open the refrigerator door. The Riseman was much more readable, but this would not happen if you were measuring in a stable temperature environment. South Florida air has a humidity level generally just a tick or two off from being rain. Even this time of year we are in at about 82-85% humidity. This point was further illustrated in the next test in the freezer where both watches turned into Frosty mugs (see pictures). Unfortunately I went past the temperature measuring capabilities of the Riseman so it would not display a temperature yet the time and barometer where working. My ski thermometer read -15degrees F in the freezer and the Ball was reading -27 degrees C or -16.6 degrees F. Given what I’ve seen here I would trust the TMT to give me a reasonably accurate reading off the wrist if needed. When still frosty I checked the second hand after three hours and we were spot on against the atomic clock. I allowed the two to warm some in the sun and as the Riseman got back in it’s range (-10C) it started to read again. Both watches apparently read off of the case back so they must be off the wrist to read accurate for 10 minutes according to( page 37 of) the online Ball manual ( http://www.ballwatch.com/images/cust...ALL_UM_ENG.pdf ).
So hot, cold or somewhere in the middle the Ball demonstrated accuracy under this extreme condition using the recommended measurement process.
Freezer and just out of it pictures:
Now some details about the watch. This has a T25 dial marking with 31 GLS tubes in the dial hands and bezel. The white on black numbers in the outer register of the thermometer are GLS backlit so temperatures can be read at night since the thermometer pointer is also GLS lit. This watch uses a SS case with the thicker EHC generation 1 bezel with the GLS pip (Maybe this should be Gen II since early EHC had a Luminova triangle pip). The Crystal/Dial diameter is 29.5mm, the case and bezel measure 40mm and it is 46mm wide to the tip of the (1st generation) crown. The watch is 50.5mm lug-lug which is 2mm shorter than the Spacemaster. Lug width is 20mmand the watch is 15mm thick. The bracelet has the first generation double clasp with three full and one half link on each side (6 full and two half total)plus two 2mm micro adjust positions on the clasp. The dive extension folds into the back of the clasp and allows an additional 16 mm extension. The thermometer reads from -35C to 45 C. This watch meets all the EHC standards so 7500Gs shock, 12,000 A/m magnetic resistance and has a 300M WR rating. The sapphire crystal is AR coated on the inside. This watch wears smaller than the Spacemaster and X-lume EHC models. The 4mm smaller dial size and the 2mm less in over all width and length are the key factors. I think the Spacemaster dial bezel change makes this look smaller then the measurements variant would indicate. So if you’re looking for a less overwhelming EHC this may be the right choice. The model number on this watch is DT1016A-SAJ-WH for the white dial with blue hands version I have here. Change the the last two letters in the model number to BK for the black dial with SS hands. While this watch is no longer a current model in the US, the Ti variant still is. This watch was still in all the factory wrappings when I got it and has maintained COSC timing throughout my tests (Not a COSC model). According to the Ball site this movement is shared with the EHC Ti TMT, TMT diver and the Trainmaster TMT.
Having fared very well here in Florida this will be going back in a few days to Rob once I’m certain I have all my pictures that I need. I am very impressed with the accuracy this watch has exhibited though my tests and have a great respect to the TMT temperature module. I may have to consider the TMT diver to round out my collection in the near future.
Enjoy the rest of the pictures.