speedo face repair

[kevin powles]

Hi, If I were you I would leave the speedo face well alone !. I work in a Nuclear Power Station and took a Mk2 speedo to work the other week to make up an outer ring to mount it to the instrument facia. On leaving radiological controlled areas we routinly put stuff in a small articles monitor (SAM), I put the speedo in with my tools, the messgae from the SAM was to contact the Health Physics department immediately, What you have here is a gauge painted with RADIUM paint, highly radioactive. The radium was mixed into a paint with a phosphorescent agent that emitted light after absorbing the radiation from radium's decay process. Radium and its progeny are a part of the natural uranium decay chain but have been concentrated from its natural state for this use. Radium (and its progeny) emit alpha, beta, and gamma radiation. All of the alpha radiation and most of the beta radiation is stopped by the glass cover of the instrument. The gamma radiation passes through the glass and is easily detected by most radiation meters. Leave it well alone !. If you have a Mk1 speedo gauge these do not contain Radium. If you need a Mk2 gauge I have a couple of new old stock ones here in near mint condition which i will trade for carrier parts.