Casio fx-61F Electronic Formula 27 Calculator My old trusty Casio fx-61F “Electric formula 27” calculator is still going strong and gets regular use. It was bought in a sale from Maplin [...] 12th February 2018
Digital multimeter calibration for voltage, resistance and current I got a little carried away with this one! I have an old multi-meter whose calibration was unknown. Surely an accurate voltage reference would help with [...] 7th June 2017