Introduction
Founded in the United States and today based in Switzerland, Ball Watch has built its modern identity around robust mechanical watches incorporating practical engineering solutions, from its signature self-powered micro gas tube illumination to sophisticated shock-protection systems. The Ball for BMW collection took that philosophy in an automotive direction, combining the watchmaker's technical approach with design cues developed around BMW.
The TMT Chronometer is one of the more unusual watches from the collaboration. Its defining feature is Ball's Temperature Measurement Technology, or TMT, which uses a mechanical bimetallic coil to measure ambient temperature across a range of approximately -35°C to 45°C. The indication occupies the lower portion of the black dial, joined by a date aperture at one o'clock and Ball's characteristic tritium gas-tube illumination. Beneath the dial is the automatic RR1601-C calibre, based on the ETA 2892 and fitted with Ball's proprietary thermometer module, while COSC chronometer certification adds another layer of technical credibility. Limited to just 999 pieces, this example is individually numbered 638/999.
Loupe This Scorecard
Grade
M 8.5
Status
Vetted & Approved
Included
Box, guarantee, booklet and hangtag
Est. value range
$2,000 – $4,000
The Details
Brand
Ball
Dimensions
44mm
Model
TMT Chronometer
Movement
Automatic cal. RR1601-C
Reference
N/A
Bracelet
Rubber strap
Year
Circa 2016
Condition
Excellent
Material
DLC-coated stainless steel
Included
Box, guarantee, booklet and hangtag
Dial Color
Black
THE DIAL
The black dial combines conventional hours and minutes with a date aperture at one o'clock and the TMT thermometer display sweeping across its lower portion. Fourteen self-powered micro gas tubes provide Ball's distinctive low-light illumination.
THE CONSTRUCTION
At 44mm, the DLC-coated stainless steel case gives the TMT Chronometer considerable wrist presence and is rated to 100 metres of water resistance. A screw-down crown, sapphire crystal, 4,800 A/m magnetic resistance and Ball's Amortiser anti-shock system reinforce the watch's deliberately technical character.
TIMING MACHINE READOUT
This reading was taken (crown down) with a ONEOF Accuracy Boutique Edition timing machine at time of cataloging. It is provided as a courtesy only, and shall not be construed as a warranty or guarantee of any kind. Please refer to our terms and conditions of sale for more information.
Condition
Watch is in overall excellent condition. The DLC-coated steel case shows only light signs of wear, with a few surface marks and a couple of small scratches to the coating on the case side. The steel case back has surface scratches and marks while retaining well-defined engravings. The BMW logo-embossed winding crown is in excellent condition. The dial and hands are in near-mint condition. It is fitted with a black rubber strap showing signs of wear and a steel Ball pin buckle. Comes with the inner and outer boxes, guarantee card, certificate, booklet and hangtag.
Our Perspective
The TMT Chronometer is an intriguing example of Ball's tendency to incorporate genuinely unusual mechanical functions into otherwise practical sports watches. Its mechanical thermometer, COSC-certified movement, tritium illumination and BMW connection give it considerably more character than a conventional automotive collaboration, while production of just 999 pieces adds an appealing degree of rarity.
