Operating Manual

Accu-Wave Chapter 4 Set up Additional Measurements
TN Technologies 4-3
• pound pounds
• metric ton 1000 kg
• short ton 2000 lbs
• long ton 2240 lbs
• oz avoirdupois ounces
After specifying the mass units, you next enter the density of your material. (Mass is
computed as the specified density times the volume measurement.) The value entered for
the density must be in the same units (mass/volume) as specified for the mass and volume
measurements. For example, if you select “pounds” for the mass units and “cu ft” for the
volume units, the density must be entered in units of pounds/cu ft.
Rate Measurement
The rate measurement computes the time rate of change for the selected measurement. The
rate can be computed for any measurement assigned to a measurement number. The rate
can always be computed for the primary measurement (measurement 1). Other
measurements must be set up using the “Assign and set up measurement” menu before the
measurement rate can be computed.
Note: The rate measurement should be set up after setting up the measurement
for which you wish to compute the rate. That is, the number of the rate
measurement should be larger than the number of the base measurement.
The “smallest change for rate” menu item sets a threshold for the change required in the
measurement before the gauge computes a rate value. No rate is computed until the
magnitude of the change in the measurement value exceeds the threshold. Once a rate value
has been computed (i.e., the change in the measurement exceeds the threshold), a new rate
is computed when the threshold is again exceeded, or at the time when the change in the
measurement should have exceeded the threshold based on the last computed rate estimate.
This allows the estimated rate to settle back towards zero if the change in the process
measurement stops.
The “rate smooth factor” menu item determines the degree of smoothing applied to reduce
fluctuations in the rate measurement via exponential averaging. A factor of 1.0
corresponds to no smoothing (estimated rate equals the last computed rate). Use a smaller
rate smooth factor if the measurement tends to fluctuate rapidly, resulting in noisy rate
readouts. The minimum factor is 0.01 and corresponds to the greatest amount of
smoothing.
The “rate time code” lets you select the time interval associated with the rate measurement.
For example, you can measure the change in level per second, per minute, etc. Select from
the following set of time intervals:
• s seconds
• m minutes
• h hours
• d days
• w weeks