FAHM ULM84 Series, User Manual

Page: 6 / 21

Ultrasonic Level Transmitter
ULM84 Series User Manual
Dec.2020
Page 6 of 21
www.faraboard.com
FAHM Co.
Industrial Automation
Doc. ULM84 Rev.99-12
7. Measurement Modes
The device lets the user choose which quantity to measure; i.e. the user can choose to measure Level,
Distance, Volume or the Mass.

Level Mode
In this case, the output current value of the transmitter would be proportional to the liquid level.

Distance Mode
In this case, the output current value of the transmitter would be proportional to the distance; in other
words, if for a level, the output current value in Level Mode be A and in Distance Mode be B, the value of
A and B would satisfy the equation A+B=20 mA.


Volume Mode
In this case, the output current value of the transmitter would be proportional to the volume. The user has
also the option of following two methods to choose to calculate the volume.
a- The volume is calculated based on the level, it makes sense when the shape of the tank is symmetrical.
b- The user provides a lookup table of level-volume pairs (max 10 entries) and the volume is calculated
using this lookup table.

Mass Mode
In this case, the output current value of the transmitter would be proportional to the mass. The user has
also the option of following two methods to choose to calculate the mass.
a- The volume is calculated based on the level and the mass calculated based on the volume, given that
the user has provided the density. This method makes sense when the shape of the tank is symmetrical.
b- The user provides a lookup table of level-volume pairs (max 10 entries) and the volume is calculated
using this lookup table, then the mass is calculated based on the volume and provided density.
8. Display Modes
The devices provides users with different modes to display measured results, current output, … that
follows; please note that the chosen display mode has no effect on the current output and the current
output is only determined by settings done in previous section.

Level / Other Variables Display Mode
In this mode, the liquid level is displayed alongside with one optional variable; the value of transmitter’s
current output is also displayed and the percent of current output in both numeric and graphical
presentations are available.
In this modes, in addition to the level, the user can choose between distance, volume, mass, temperature
or any custom variable (CV) to be displayed.
x R0010 D10 S0
METER 7.714 Level:
METER 2.286 Dist.:
16.342 mA
77.14%
Figure 12- Level/Distance display mode
This mode is illustrated in the above figure by displaying Level/Distance and in the following figure by
displaying Level/Volume.
x R0010 D10 S0
METER 7.714 Level:
Liter 6241.22 Vol.:
16.342 mA
77.14%
Figure 13- Level/Volume display mode