6
M E A S U R E M E N T
R A N G E
C A L C U L A T I O N S
Ultrasonic non-contact devices are typically rated for a
maximum range in ideal conditions. Experience has shown
that maximum range must be reduced for certain factors.
Although the maximum range rating is somewhat conserv-
ative, each application must be evaluated for specific con-
ditions in the tank.
H O W
T O
C A L C U L A T E
To evaluate the performance of a 344 or 345 in a particu-
lar application, use the chart on page 7, and follow the
steps below:
1. Select one condition from each of the operating
parameters that best describes your application.
2. Enter the corresponding performance multiplier value
in the application column.
3. Multiply all of the selected values together.
4. Multiply step 3 by the maximum potential range of the
unit. This yields a value that is the maximum allowable
measurement range for the application.
E X A M P L E
The vessel is a closed-top tank, 26-feet tall and is filled from the top.
Surface agitation
Expect slight agitation from fill line: Performance multiplier 0.9
Vapor and steam
The process temperature is +130° F, slight vapor is expected:
Performance multiplier 0.9
Beam interference
No interference exists: Performance multiplier 1.0
Transducer alignment
The transducer will be perpendicular to the liquid surface:
Performance multiplier 1.0
Foam
None: Performance multiplier 1.0
Dust
None: Performance multiplier 1.0
Air movement
None: Performance multiplier 1.0
Ambient temperature
0 to +120° F: Performance multiplier 1.0
Pressure
Atmospheric pressure: Performance multiplier 1.0
Will the Model 344 work for this application?
C A L C U L A T I O N
Multiply all values in the application column:
0.9 x 0.9 x 1.0 x 1.0 x 1.0 x 1.0 x 1.0 x 1.0 x 1.0 x 35 feet (maximum) = 28.35 feet
The calculation yields 28.35 feet as the new maximum range. Since the tank is 26 feet tall, this application will give
satisfactory results with the Model 344.
NOTE:
The performance multipliers provided are conservative estimates. Since these factors are subjective, the values have
been designed to provide very high confidence of system success. Contact the factory if there are any questions
concerning the interpretation of any of these performance multipliers.
Sensor alignment
Beam spread
interference
Beam spread
interference
Air movement
Dust
Vapors
Foam
Surface
agitation
