https://www.npl.co.uk/open-day Tickets are available for different entry times. My experience is the day is never long enough, so one really wants to be there as early as possible. There's tons of stuff on time-keeping there, and also some on voltage measurements. I cc'ed to both time-nuts and volt-nuts, although I suspect there's a fair number of people who are members of both groups. My past experience is that NPL does a very good job of these open-days. They manage to get plenty of things of interest to young children, yet there's plenty of stuff to get PhDs scratching their heads. To you guys in the USA or elsewhere, where places like NIST do not have open-days, perhaps you can use the fact NPL does, to get your own national metrology labs to have open-days. Dr David Kirkby Ph.D Email: drkirkby@kirkbymicrowave.co.uk Web: https://www.kirkbymicrowave.co.uk/ Kirkby Microwave Ltd (Tel 01621-680100 / +44 1621-680100) Stokes Hall Lodge, Burnham Rd, Chelmsford, Essex, CM3 6DT.