A PICAXE refurbishes a 40-year old autoranging Volt-Ohmmeter.
A standalone AC wattmeter measures true watts from 20 to 2000 full-scale. it also measures and displays current and line voltage, and accumulated watt-hours
A logger with an opto-isolated current input, analog meter, and SD Writer
This is both an altimeter and a barometer depending on the code.
A small ADC with RS-232 Output
A counter using ancient Beam-X tubes
An interface for a sensor for Carbon Dioxide, Methane and LPG gas. It displays and transmits messages of its measurements.
A multi-meter with digital and simulated analog output using neopixels
A device to test transistors
A 2-input voltmeter with serial output
This is used for measuring rechargable batteries.
Uses an exceptionally sensitive meter
Audio-frequency sensitive voltmeter
A portable meter to measure DC or AC currents with ranges from 50 micro-amperes to 5 amperes
Uses a bridge circuit capable of measuring in-citcuit
An adapter to measure the current and power consumption of line-powered devices.