Instruments {altimeter}| can measure height.
Wind speed measurement uses spinning devices {anemometer}|, which generate electric current to move a dial.
Air capsules {aneroid barometer}| can compress or expand to measure air pressure.
Instruments {barometer}| can measure air pressure, typically using mercury columns.
Instruments {calorimeter}| can measure heat produced by burning masses.
Instruments {cardiograph}| can measure heartbeat rate.
Electrically operated pens on revolving drums {chronograph}| can record short durations and rapid changes [1849].
Instruments {colorimeter}| can measure color in fluid.
Instruments {dynamometer}| can put loads on engines and measure force and work.
Phototubes {heat sensor}| can sense infrared light. People and animals radiate infrared light, as do hot machinery and exhaust, so heat sensors have military uses. Heat sensors also detect light-level changes for television cameras.
To visualize air density, a straight edge and mirrors {interferometer}| {Schlieren interferometer} can make an interference pattern. Optical interferometers allow sharp images through atmosphere.
Photocells {light meter}| can measure light amount and can have a film-type dial.
Instruments {manometer}| {sphyngomanometer} can measure blood pressure.
Thermometers {meat thermometer}| can measure temperatures from 120 to 210 F. Put meat thermometer in thickest meat part, thigh away from bone for turkey and lean center part for other meats. For beef, temperature of 170 is well done, 160 is medium, and 140 is rare.
A flexible shaft with wire inside can go from car wheel to dashboard dial {odometer}|. Rotating wheel rotates wire, which turns gear connected to counter. The same wire is for speedometer.
Instruments {oscilloscope}| can measure frequency and amplitude.
Instruments {pedometer}| can measure steps per minute.
Instruments {planimeter}| can measure area, using an extensible rotating arm.
Instruments {polarimeter}| can measure light polarization angle.
Lie detectors {polygraph}| can use decreased skin resistance from more sweating to indicate lies. To detect body changes associated with lying, measure skin electrical resistance, breathing rate, and heart rate. Lie detectors are best on statements asking about person's activities or about details, to see if person was there or not.
Instruments {pychnometer}| can measure specific gravity.
Thermometers {pyrometer}| can measure radiation intensity for wavelength range.
Instruments {radiometer}| can measure electromagnetic radiation intensity by reflection from surface.
Instruments {seismometer}| can measure earth movements in earthquakes.
Instruments {spectrograph}| can measure intensity at wavelengths.
Instruments {spectrometer}| {spectrophotometer} can measure light intensity passing through material or solution at a wavelength.
Instruments {spectroscope}| can measure intensity at a wavelength.
Flexible shafts with wire inside run from car wheel to dashboard dial {speedometer}|. Rotating wheel rotates wire, which turns magnet behind aluminum disc, to set up electric current, which moves dial needle. The same wire is for odometer.
Instruments {spherometer}| can measure surface curvature.
Instruments {spirometer}| can measure air volume and flow rate inhaled and exhaled by lungs.
Instruments {tachometer}| can measure revolutions per minute.
Instruments {tensiometer}| can measure tension.
Temperature instruments {thermometer}| can be tubes with vacuum and mercury or alcohol inside. Mercury or alcohol expands as temperature increases.
Electric clocks {clock} use synchronous motors, which turn at 60 cycles per second, USA AC-current frequency. Electric motor replaces pendulum, escapement, and spring or weight.
Clocks {atomic clock}| can use cesium-atom vibrations to establish frequency.
Clocks and watches can have oscillating wheels {balance wheel}| that determine frequency.
Clocks {cesium clock}| can depend on cesium emission-spectrum wavelength.
very accurate clock {chronometer}|.
Clock parts {escapement}| can transfer power from main spring to gears, by oscillating. Escapement has pendulum, ratchet, and gear.
spring
Springs {mainspring} are coiled or flat steel ribbon, which is wound to provide energy.
oscillation
Clocks with a hanging pendulum use gravity for back-and-forth oscillation. Weight hangs on chain, as in cuckoo clocks. Clocks with a circular pendulum use a hairspring and lever for oscillation.
Pendulum connects to ratchet, which engages gear teeth. Alternatively, ratchet can press against gears to escapement wheel, so wheel turns one notch if released by ratchet. The mechanism pushes ratchet lightly, which pushes pendulum slightly and keeps pendulum moving in spite of friction.
process
Oscillation in one direction moves gear one step forward. Oscillation in other direction moves ratchet into position to receive next forward motion. Oscillation takes a fixed time, which shortening or lengthening can adjust.
Two spherical chambers can have narrow constriction between them through which fine sand flows {hourglass, clock}|.
Maser clocks {hydrogen clock}| depend on hydrogen emission wavelengths and are accurate to one part in 10^15.
Clocks {quartz clock}| can use quartz-crystal oscillations in escapement. A battery provides current that oscillates crystal.
Clocks {timer}| can mechanically or electrically start or start movements, at specific times.
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Date Modified: 2022.0225