Racal Dana 1992 / 1991 / 1999 - Can it time - Page 1
Forum section: electronics / general

author: mendip_discovery
author_rank: Super Contributor
timestamp: April 27, 2021, 07:34:58 pm
content: I have been offered a Racal Dana 1991 / 1992 / 1999 and I believe they can be used as a high accuracy time for the checking of stopwatch etc.Anyone able to confirm they can do this and which one is the better?I remember I used to have a counter/timer in a lab I worked in before and we could use it to count time which was handy.It is been offered at the right price and I plan to get a cert and use it for some of the general stopwatch/timers as a traceable bit of kit.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: April 27, 2021, 08:08:29 pm
content: Quote from: mendip_discovery on April 27, 2021, 07:34:58 pmIt will only be as accurate as it's internal time base... some have an ovenised option.https://accusrc.com/uploads/datasheets/racal-dana-1992-datasheet.PDFhas some specs.Quote from: mendip_discovery on April 27, 2021, 07:34:58 pmHow much?

author: bdunham7
author_rank: Super Contributor
timestamp: April 27, 2021, 08:15:34 pm
content: Yes, they are a counter/timer, but for high speed electronic circuits. I'm not at all sure how you would use them to calibrate a manually-operated stopwatch, if that is what you are doing. But all that aside, the main problem will be that if the front switches aren't already rubbish, they likely will be as soon as you start using it.

author: mendip_discovery
author_rank: Super Contributor
timestamp: April 27, 2021, 08:52:19 pm
content: I did just spot a video on YT of a chap using a 1Hz from a frequency generator and just counting the numbers.Price ~£200 but the boss will only let me buy 1 so I have to be definitive on it. I work at a cal lab and looking for stuff that will grow the capabilities and traceability.Just reading manuals and I think we had a 9902 which had a stop/start button on the front and using the Time Interval Function.The 1992 has the option to count the time between A and B channels firing (switch). The 1nsec resolution with a time range of 8 x 105Jack

author: Andy Watson
author_rank: Super Contributor
timestamp: April 27, 2021, 10:10:33 pm
content: Quote from: mendip_discovery on April 27, 2021, 08:52:19 pmThey can resolve to 1ns, however, the display is only 9 digits.The 199x series are good devices, but note the following deficiencies:Unlike some of the previous Racal counters they do not have a "contact" setting. I.e. you can't wire-up a push button to the inputs and expect it to work - you have to provide an active signal. And speaking of contacts, the counters have limited facility for dealing with contact-bounce - this may or may not affect you.They do not remember any digital settings when the power is removed - every time you turn them on you will have to set/reset it to the state that you want. In the case of the 1991/1992 this includes setting the trigger levels (I believe some of the other models have analogue pots to set the trigger - but it's still a PITA).The 199x series are decades old now - most of them will be desperately trying to climb out of the bathtub of reliability.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: May 01, 2021, 06:43:20 pm
content: Quote from: mendip_discovery on April 27, 2021, 08:52:19 pmI have a 1992 (I think) in the loft that I could probably let you have for £100+P&P. I doubt it's worth much more than that. If you are interested I will dig it out and send some photos