Notation	Name	Description	Status
126	Gravimetric moisture determination	Measurement of the amount of water in soil by weighing a samp...	stable
128	Soil heat flux plate		stable
159	Neutron probe	Measurement of the moisture content and hence the porosity of...	stable
187	Electrical resistance blocks (Porous blocks)	Determination of electrical resistance between two electrodes...	stable
194	Soil thermometer		stable
200	Tensiometer	Measurement of soil capillary tension by means of a porous cu...	stable
203	Time domain reflectometry (TDR)	Estimation of water content in unsaturated materials based on...	stable
260	Ultrasonic ranging	Transmission of an ultrasonic pulse towards the target and li...	stable
261	Graduated device	Manual measurement or observation made with a graduated fixed...	stable
262	Snow pillows and snow scales	Weighing of snow-cover mass per unit area.	stable
344	Laser ranging	Emission of a modulated beam of light in the visible spectrum...	stable
345	Echo sounding	Evaluation of the return time of acoustic waves emitted into ...	stable
346	Frequency domain reflectometry	Measurement of soil capacitance by means of radio frequency w...	stable
347	Gamma-ray attenuation	Determination of gamma-ray attenuation at given depth of soil...	stable
348	Non-recording gauge	Determination of water stage by means of a non-recording gaug...	stable
349	Staff gauge	Determination of water stage by means of a graduated vertical...	stable
350	Inclined gauge	Determination of water stage by means of a non-vertical scale...	stable
351	Wire-weight gauge	Determination of water stage by means of a fine cable or wire...	stable
352	Point gauge	Level measurement gauge, the essential element of which is a ...	stable
353	Maximum-stage gauge	Determination of the elevation of the flood crest by the adhe...	stable
354	Recording gauge	Determination of water stage by means of a recording gauge, f...	stable
355	Wire-float recording gauge (hydrograph)	Determination of water stage by means of a gauge consisting o...	stable
356	Pressure-actuated recording gauge	Recording gauge operating on the principle that static pressu...	stable
357	Velocity-area method	Method of determining the discharge of a stream by measuring ...	stable
358	Float gauging	Measurement of the velocity of a stream by means of timing th...	stable
359	Dilution gauging	Determination of the discharge of a stream by measuring the d...	stable
360	Slope-area method	Determination of the discharge in a reach which is based on t...	stable
361	Measuring weir	Determination of the discharge of a stream by means of a devi...	stable
362	Flume	Determination of the discharge of a stream by means of a man-...	stable
363	Stage-discharge relation	Determination of the discharge of a stream by means of a rela...	stable
364	Water current meter	Determination of water velocity by means of a current meter, ...	stable
365	Cup-type current meter	Determination of water velocity by means of a current meter w...	stable
366	Propeller-type current meter	Determination of water velocity by means of a current meter i...	stable
367	Acoustic (ultrasonic) velocity meter	Measurement of the difference in travel time of acoustic (ult...	stable
368	Acoustic doppler current profiler (ADCP)	An instrument that uses an acoustic doppler transducer to mea...	stable
369	Acoustic doppler current meter	Determination of stream velocity by means of an acoustic Dopp...	stable
370	Optical or nuclear suspended-sediment gauge	Determination of the decrease of intensity of a visible light...	stable
371	Gravimetric sediment measurement	Estimation of the total sediment in a water sample by allowin...	stable
372	Displacement method of sediments	Determination of sediment concentration by the measurement of...	stable
373	Water discharge-sediment discharge rating curve	An empirical relationship relating sediment discharge and str...	stable
374	Water discharge-bed material rating curve	An empirical relationship relating bed-material discharge and...	stable
375	Volumetric method	A process for measuring the discharge of a well, spring, or s...	stable
376	Electromagnetic current meter	Determination of water velocity based on the principle that a...	stable
377	Stream index-velocity rating	Computation of stream discharge based on a relation between s...	stable
378	Acoustic doppler velocity meter (ADVM)	Determination of water velocity by using the Doppler principl...	stable
379	radar water level gauge	A radar water level gauge transmits microwave energy to measu...	stable
380	radar velocimetry	Radar velocimetry or surface velocity radar (radar sensor) is...	stable
381	image velocimetry	The measurement of velocities at the free surface of a moving...	stable
419	Frequency domain reflectometry	Measurement of soil capacitance by means of radio frequency w...	stable
420	Gamma-ray attenuation	Determination of gamma-ray attenuation at given depth of soil...	stable
421	Non-recording gauge	Determination of water stage by means of a non-recording gaug...	stable
422	Staff gauge	Determination of water stage by means of a graduated vertical...	stable
inapplicable	inapplicable	None of the codes in the table are applicable in the context ...	stable
unknown	unknown	The measurement/observing method is unknown.	stable