Sensors

Calibrating a Humidity Sensor with Saturated Salt Solution — ASTM E104 Method Why Calibrate? The music room contains a pair of B&W Matrix 800 loudspeakers — the original flagship model from 1987. At 110kg each, with crossovers, drive units, and cabinet materials that are no longer manufactured, they are effectively irreplaceable. Keeping them in good condition over decades requires stable humidity. Too dry and surrounds crack, spiders stiffen, and wooden cabinet joints open. Too damp and cones absorb moisture, crossover components corrode, ferrofluid in the tweeters degrades. And most importantly with this pair, the nickel plated magnet assemblies oxidise, binding the voice coils in the coil gap. This has already killed one of the very rare drivers. ...

Reviving a Weather Underground Station with Home Assistant and ESPHome Station IBRIGHTO3 had been dormant for years. Reviving it required no dedicated weather station hardware — just sensors already deployed around the house, a few template conversions in Home Assistant, and a REST command firing every five minutes. Hardware The station currently reports three parameters: Temperature and humidity — AirGradient O-1PS outdoor sensor (SHT40), reporting via MQTT to HA Barometric pressure — DPS310 sensor on an ESP32-C6, integrated via ESPHome native API The DPS310 is a good choice for pressure — it is a high-resolution MEMS barometer with better temperature compensation than the commonly used BME280, and ESPHome has native support for it. ...