Ultrasonic Level Transmitter
ULM84 Series User Manual
Dec.2020
Page 3 of 21
FAHM Co.
Industrial Automation
Doc. ULM84 Rev.99-12
2- To retrieve the best wave response, the angle between the probe and the level should be right
angle.
3- There should be no bubble on the liquid level.
4- Never install more than one transmitter in a tank to prevent wave interference.
5- In vault roofed tanks, don’t install the probe onto the center of the vault.
6- Regarding the angle of transmitted waves and the height of the tank, the installation place
should be at least 30cm to 1m far from the tank wall.
7- There should not be any obstacle like thick wall, stairs, and pipe and ... in the path of transmitted
and retrieved ultrasonic wave.
8- The transmitter should be kept far from direct sun light and preferably rain.
For example in Figure 1 tank with vault/dome-shaped floor, the transmitter shouldn’t be installed on the
right part (according to rule #7) or at the center (rule #5); it should be installed on left part with a suitable
distance from the wall (rule #6) and from the liquid level (rule #1).
Finally regarding tank conditions and
choosing the correct installation location, the transmitter is mounted using bracket, flange or thread nut.
Figure 3- Mounting methods
4.
Wiring
There are two possible ways to do the wiring. If the goal is to read the transmitter’s current or to apply it
to the current input card, the wiring should be done according to figure 3.but if the goal is to connect to
the device through HART protocol, the wiring should be done as illustrated in figure 4.
Figure 3- Wiring diagram to read the transmitter’s current
Figure 4- Wiring diagram to enable HART connection
5.
Transmitter Startup
When
the
supply
voltage
applied,
the
device
displays
the
name
of
the
manufacturer,
transmitter
model and
FAHM Co. Instruments
Model ULM84
S/N: 14BE1005
Searching …
Figure 5- Start-up screen
Bracket Mounting
Flange Mounting
Thread Nut Mounting
Hole Diameter
65~75 mm
mA
Ammeter Digital PLC
DC24V
Shield Layer Earthed
RVVP2x0.5 Cable
Instrument
Precision
Resistance 250
Ù
DC24V
Shield Layer Earthed
RVVP2x0.5 Cable
Instrument
HART
250 Ω
