462 CHAPTER 8. LABORATORY MEASUREMENT AND ANALYSIS
the expectations of the investigator. Deciding which quantities to measure
is a function of one or more of the following factors:
• Measurement capability (can the desired measurement be
made?)
• Instrument availability and/or cost
• Available skilled technical support
• Available methods of analyzing the measurements
• Conformance to past studies
• Measurement repeatability
In some instances a direct measure of a particular physical quantity will
not be possible, in which case we may be able to measure a parameter
that can be theoretically related to the parameter of interest. For example,
a direct measure of wavelength could be difficult, so instead we usually
measure wave period and water depth and calculate wavelength from the
dispersion relation.
Laboratory measurements can be categorized in a number of different
ways. Here, we shall group measurements according to the following five
broad divisions.
1. Geometrical Measurements
2. Fluid Property Measurements
3. Fluid Motion Measurements
4. Force and Transport Measurements
5. Other Environmental Measurements
These categories should encompass most of the common measurements encountered in hydraulic laboratory experiments and coastal physical models.
Typical measurements corresponding to each of the five categories of
measurement are given in the following lists. The lists are by no means
complete.
• Geometrical Measurements pertain to the fundamental unit of length (or angle). Typical geometrical measurements include:
— Prototype boundaries or solid objects scaled to model
size
Different positions and elevations in the model relative
to a fixed coordinate system
the expectations of the investigator. Deciding which quantities to measure
is a function of one or more of the following factors:
• Measurement capability (can the desired measurement be
made?)
• Instrument availability and/or cost
• Available skilled technical support
• Available methods of analyzing the measurements
• Conformance to past studies
• Measurement repeatability
In some instances a direct measure of a particular physical quantity will
not be possible, in which case we may be able to measure a parameter
that can be theoretically related to the parameter of interest. For example,
a direct measure of wavelength could be difficult, so instead we usually
measure wave period and water depth and calculate wavelength from the
dispersion relation.
Laboratory measurements can be categorized in a number of different
ways. Here, we shall group measurements according to the following five
broad divisions.
1. Geometrical Measurements
2. Fluid Property Measurements
3. Fluid Motion Measurements
4. Force and Transport Measurements
5. Other Environmental Measurements
These categories should encompass most of the common measurements encountered in hydraulic laboratory experiments and coastal physical models.
Typical measurements corresponding to each of the five categories of
measurement are given in the following lists. The lists are by no means
complete.
• Geometrical Measurements pertain to the fundamental unit of length (or angle). Typical geometrical measurements include:
— Prototype boundaries or solid objects scaled to model
size
Different positions and elevations in the model relative
to a fixed coordinate system