1/100 minute analog timer - what for? - Page 1
Forum section: electronics / general

author: metrologist
author_rank: Super Contributor
timestamp: September 11, 2023, 06:02:10 pm
content: I have this timer but instead graduated to 100, and without a minute hand (it has the center minute circular piece but no arm) and the reset does not reset the minute, which seems intentionally built that way.What would such a timer be used for? I understand decimal timers but one that only counts to 1 minute?https://www.ebay.com/itm/155035806178

author: TimFox
author_rank: Super Contributor
timestamp: September 11, 2023, 06:15:15 pm
content: According to the eBay listing, it's a darkroom timer.Are you sure you understand the calibration correctly?

author: metrologist
author_rank: Super Contributor
timestamp: September 11, 2023, 06:52:31 pm
content: Yes, but what I read is that developing time is generally minutes and exposure is in seconds, and all "darkroom" timers I've seen are graduated in seconds with a minute hand. I'm pretty sure the hand did not just break off as the circumference is fully painted and smooth, and also that there is no internal lever to reset the minute wheel...With 100 units to the minute, it's not too easy to figure out where 17 seconds is, for example.Calibration? Yes, I popped the hood and there is what I think is called a regulator thingamajig. I have one of those regulator apps on my phone too, I think called a timegrapher.Operation is simple. The left lever has run and stop positions. The right lever is spring loaded and resets the 0.6 second hand only.I was half tempted to glue on a minute hand until I realized the minute wheel is not reset. I'd have to figure out that part of the mechanism.

author: thm_w
author_rank: Super Contributor
timestamp: September 11, 2023, 08:42:35 pm
content: https://www.ebay.com/itm/166255177630https://afterglowretro.com/2013/08/21/junghans-darkroom-laboratory-sports-timer-made-in-germany-circa-1950s/https://www.hanhart-stoppuhren.com/en/products/precision-mechanics/split-seconds-addition-timer/23/split-seconds-addition-timer-1/100-min.-industry-modelMaybe a 60s timer with 1/100ths of a second and the 1/100ths hand is broken?

author: metrologist
author_rank: Super Contributor
timestamp: September 12, 2023, 12:44:22 am
content: One revolution is one minute. Maybe a decimal minute is more common in other countries. I'm an American ogre.

author: jfiresto
author_rank: Frequent Contributor
timestamp: September 12, 2023, 06:15:01 am
content: Decimal clocks and stopwatches are commonly used for time and motion studies.

author: ebastler
author_rank: Super Contributor
timestamp: September 12, 2023, 11:43:21 am
content: Quote from: metrologist on September 11, 2023, 06:02:10 pmIf it does not have a minute hand, how would you expect it to reset the minute?

author: rstofer
author_rank: Super Contributor
timestamp: September 13, 2023, 01:19:13 am
content: Quote from: jfiresto on September 12, 2023, 06:15:01 amAnd sports car rallies where time is in 0.01 minutes and distance is in 0.01 miles.https://www.scca.com/pages/road-rally-events

author: metrologist
author_rank: Super Contributor
timestamp: September 13, 2023, 03:30:05 pm
content: Quote from: ebastler on September 12, 2023, 11:43:21 amIt has all the mechanics: wheels, shafts, and there is a round disc at the very front that I observe moving at minute pace. It's like the hand itself was broken off but that isn't the case because the circumference is smooth painted. It would be a much more useful timer if the minute hand were present and I could glue something on there or make a hand, but not being able to reset that make it pointless.

author: metrologist
author_rank: Super Contributor
timestamp: September 13, 2023, 03:37:31 pm
content: OK, I bet it had sports application, like 100 meter dash.