Dwyer Instruments Series ULT Installation and Operating Instructions

Series ULT Ultrasonic Level Transmitter

3 29/32

[204.79]

4 9/32

By Dwyer

Specications - Installation and Operating Instructions

Bulletin L-45

Series ULT Ultrasonic Level Transmitter provides reliable, accurate, noncontact
measurement of liquid levels. Ultrasonic non-contact technology offers no moving parts
to wear, jam, corrode, or get coated like contact technologies. Mapping software makes

effective measuring surface only a 3˝ diameter column. No concerns with ladders,

pipes, or other tank intrusions in the remaining sound cone. Unit is FM approved
explosion-proof making it ideal for use in hazardous locations. The ULT features easy
programming with 6 digit LCD display and simple menu structure. Output range is

adjustable with choices of inputting tank dimensions or just ll and empty the tank

while calibrating and it automatically scales to levels it senses. Window cover allows
early viewing of display. Failsafe output options and diagnostic capabilities makes the
ULT a good choice for critical applications.

MODEL CHART
Example ULT 1 1 ULT-11

Series ULT Ultrasonic level transmitter

Range 1224.6´ (7.5 m)

Options 122˝ NPT male process with 1/2˝ NPT female conduit

32.8´ (10 m)

2˝ BSPT male process with M20 conduit

[99.21]

2X 1/2 NPT

ø3 21/64

[84.53]

8 1/16

SPECIFICATIONS

Service: Compatible uids. Not for use with powder and bulk solids.

Wetted Materials: Sensor: PVDF; Process connection: 303 SS.
Ranges: 24.6´ (7.5 m), 32.8´ (10 m).
Accuracy: ±0.2% of maximum range.
Resolution: 0.079˝ (2 mm).
Blind Zone: Under 8˝ (20 cm).
Beam Width: 3˝ (7.6 cm) diameter.
Temperature Limits: Ambient: -40 to 140°F (-40 to 60°C); Process: -4 to 140°F

(-20 to 60°C).

Temperature Compensation: -40 to 140°F (-40 to 60°C).
Pressure Limits: 30 psi (2 bar) up to 25°C (77°C). Above 25°C (77°F), rating

decreases 1.667 psi per 1°C increase. See pressure and temperature chart.

Power Requirement: 18-28 VDC (two-wire).
Output Signal: 4-20 mA or 20-4 mA (two-wire).
Max. Loop Resistance: 250 Ω at 24 VDC.

Electrical Connections: Screw terminal.

Conduit Connection: 1/2˝ NPT female (two) or M20.

Process Connection: 2˝ NPT male or BSPT.

Enclosure Rating: Weather-proof meets NEMA 4X, explosion-proof rated Class I,
Div. 1, Groups B, C, D; Class II/III, Div. 1, Groups E, F, G.

Mounting Orientation: Vertical.
Failsafe: On lost echo after 30 s, user selectable to 4, 20, 21, 22 mA or last signal.
Memory: Non-volatile.
Display: 6 character LCD.

Units: In, cm, ft, m, percent.

Memory: Non-volatile.
Programming: 4 button.
Weight: 4.0 lb (1.8 kg).
Agency Approvals: CE, FM.

[108.74]

MERCOID

A DIVISION OF
DWYER INSTRUMENTS, INC.

TEMPERATURE/PRESSURE DERATING

TEMPERATURE °C

OPERATING PRESSURE PSI

INSTALLATION

S

40

UNACCEPTABLE

30

20

ACCEPTABLE

10

RANGE

RANGE

Unpacking

Remove the ULT from the shipping carton and inspect for damage. If damage is found,

notify the carrier immediately.

Materials

The ULT may be used to detect level of a variety of materials. Since the sensing
technology is non-contact it is well suited for corrosive, coating, slurry, or sticky media.
The hazardous approval rating also makes the unit ideal for use with hazardous

rated applications. Please see the specications section for hazardous approval
classications.

0

-40 -20 0 20 40 60 80

OPERATING PRINCIPLE

Ultrasound is sound with a frequency greater than the upper limit of human hearing;
approximately 20 kilohertz. The ULT contains an ultrasonic transducer and a
temperature sensing element. The ultrasonic transducer transmits ultrasound wave
pulses through air directed towards the material of which the level is desired. The

ultrasound waves then reect off of the material as an echo and travel back to the

transducer. The level of the material is determined by the transit time of the ultrasound
wave pulse from the sensor to material and for the echo to come back to the sensor.
The speed of sound through air is sensitive to the air temperature. The ULT uses the
temperature sensing element to compensate for air temperature changes.

The ULT incorporates patented surface processing technology and adaptive signal

processing. Surface processing technology lters out all signal obstructions that may
be in the tank creating an effecting beam diameter of only 3˝ (7.6 cm). This beam

diameter is a straight column and not cone shaped like competitor units. Adaptive signal

processing continuously optimizes sensor power, output ltering, and environmental

noise rejection.

Mounting Location

• The process temperature and ambient temperature must be within the specied

limits.

• The probe must be located away from tank inlets or chutes where material may fall

on the probe during lling or emptying.

• The probe must be located at least 3˝ (7.6 cm) away from the tank side wall.

• The probe cannot be used in vacuum applications.

• The probe must be installed vertically and perpendicular to the media surface.

• Make sure the covers are accessible to allow for programming, wiring, and ability
to see the display.

DO NOT INSTALL AT

AN ANGLE RELATIVE

TO THE LIQUID

DO NOT INSTALL

WITH OBJECTS

IN THE BEAM

DO NOT INSTALL

WITHIN THREE INCHE

OF TANK SIDE WALL

DO NOT INSTALL

IN APPLICATIONS

WITH VACUUM

VACUUM

Figure 1: Unsuitable mounting locations

MOUNTING FITTING

VENTILL

LIQUID LEVEL

DIAMETER

RISER

Fittings should be selected that minimize the installation height of the transmitter so

that mounting hardware does not interfere with the acoustic signal. If the installation
does require a riser then the transmitter may be elevated up to 12˝ (30 cm) in a 6˝ (15
cm) diameter riser, 8˝ (20 cm) in a 4˝ (10 cm) diameter riser, and 3˝ (7.6 cm) in a 2˝ (5

cm) diameter riser, see Figure 2. A stand pipe may be used to dampen turbulence or

separate surface foam. Use a minimum 3˝ diameter pipe and cut to the desired length

of the transmitter span with a 45° notch at the bottom. A ventillation hole needs to be

created at the top of the pipe within the 8˝ (20 cm) blind zone, see Figure 3.

HEIGHT

INNER

ELECTRICAL CONNECTION

CAUTION

designed for AC voltage operation.

Note: Installation must be made in accordance with local codes and regulations. When
shing wire through the conduit connection do not allow the wire to touch or press on

components on the boards. Damage to the circuitry may result. Make sure that the
wire is routed so it will not interfere with the calibration switches.

CAUTION

within 18˝ (45.7 cm) of conduit entry. Disconnect power before opening, servicing,

programming, installing, or removing.

The ULT provides two 1/2˝ NPT female ports for conduit connection. The conduit

connection must be made such that condensation is not allowed to enter the sensor

housing. If necessary install a conduit breather drain in a separate conduit body to
prevent buildup of moisture. If nonmetallic conduit is used the protective ground may

be connected to the internal ground connection screw.

The ULT transmitter is designed as a two wire 4-20 mA device. Connection to the
board is through a two pin terminal block. The circuitry is polarized so the positive must
be connected to terminal 1 and the negative must be connected to terminal number

2. It is recommended that shielded twisted pair wire be used if the potential exists

for interference from external noise sources. Ground the shield at the case using the
internal ground screw and leave the other end of the shield open. Do not use the shield
as one of the current loop conductors.

Do not exceed the specied supply voltage rating. Permanent

damage not covered by the warranty may result. This unit is not

Hazardous Area Use: Plug any unused conduit openings.
Plug must engage a minimum of 5 threads. Use a conduit seal

Figure 2: Riser mounting

ATION HOLE

Ø3 [76.20] MINIMUM

Figure 3: Stand pipe mounting

BLIND ZONE

8 [203.20]

OPERATIONAL

RANGE

LOWEST