Anemometer turbines usually requires a refresh rate of wind speed measurements of 3 Hz, easily achieved by sonic anemometers. Three-dimensional sonic anemometers are widely used to measure gas emissions and ecosystem fluxes using the eddy covariance method when used with fast-response infrared gas analyzers or laser-based analyzers. Two-dimensional wind sensors are of two types: Acoustic resonance anemometers are a more recent variant of sonic anemometer. The technology was invented by Dr Savvas Kapartis and patented in 2000. Whereas conventional sonic anemometers rely on time of flight measurement, acoustic resonance sensors use resonating acoustic (ultrasonic) waves within a small purpose-built cavity in
Alcoholic spirits measure used in Scotland and Northern Ireland. The landlord can chose one or the other but not both. Thimble measures are also used in 175ml and 250ml volumes for measuring wine. Although government stamped for the correct volume, the thimble measure does rely on the user measuring the wine out manually into the thimble. Alcoholic spirits measure Alcoholic spirits measures are instruments designed to measure exact amounts or shots of alcoholic spirits. The most common products used today to measure spirits are the thimble measure and the non-drip measure, often referred to as an optic. The terms "Optic", "Optic Pearl", "OpticJade"