Dynasonics DXN Portable Ultrasonic Measurement System - Manual (Page 43)

The cgs (centimeters - grams - seconds) system uses a unit of dynamic viscosity called the poise (P). It is more commonly
expressed, particularly in ASTM standards, as centipoise (cP). The centipoise is commonly used because water has a viscosity
of 1.0020 cP (at 20 °C; the closeness to one is a convenient coincidence).
The DXN uses dynamic viscosity, expressed in cP, in the calculation of Reynolds numbers and its Reynolds
correction algorithm.
Specific Heat Capacity – (Numeric Value entered in kJ/kg x °K)
Allows adjustments to be made to the specific heat capacity of the liquid.
If a fluid was chosen from the Fluid Material list, a default specific heat will be automatically loaded. If the actual specific heat
of the liquid is known or it differs from the default value, the value can be revised. A list of alternate fluids and their associated
specific heat capacities is located in the Appendix of this manual. Enter a value that is the mean of both pipes.
Heat capacity or thermal capacity, is the physical quantity that characterizes the amount of heat required to change a
substance’s temperature by a given amount. The SI unit of heat capacity is expressed in joules per degree kelvin (J/°K).
The specific heat capacity, often simply called specific heat, is the heat capacity per unit mass of a material. Occasionally, in
engineering contexts, a volumetric heat capacity is used. The quantity used in the DXN is calculated as:
Specific Heat Capacity
kJ
kg x K
=
°
Lookup Page
Site Name 0.00 GPM
1/16/2013
2:18 PM
Meter Adv Cal System Display Site Log I/O
Create Liner Transit Doppler Fluid Pipe Lookup
Pipe Material PVC CPVC
Schedule 40
Nominal Size (in) 3
Liner Type Use Manual Entry
Figure 56: Site>Lookup
The Lookup page provides access to the DXN’s built in pipe tables. The pipe lookup tables use cascading choices to make
selections. When the Pipe Material is chosen the Schedule/Class entry becomes available. When the Schedule/Class entry is
made the Nominal Size choice becomes active.
The Site>Lookup and Site>Pipe drop-downs interact with each other. If a particular parameter is selected in one drop-down
menu it will be unavailable in the other drop-down.
The selection of Use Manual Entry for Pipe Material in the Site>Lookup screen enables the entry of non-standard parameters
using the Site>Pipe drop-down. The choice of Use Manual Entry will unlock the Pipe Material, Pipe OD, and Pipe Wall [Thickness]
inputs (see Figure 58 ).
Installation & Operation Manual
Page 43 February 2013