The Series MULS Miniature Ultrasonic Level Switch measures liquid
at a single point providing an output for high or low level alarm, overflow
prevention, or pump protection. The Series MULS uses ultrasonic wave
propagation between the transducer gap to sense the presence or
absence of a liquid. Units can be mounted within 15° of horizontal with
no additional calibration required. The switches include a 0.5 second
delay and have repeatability of less than .08 in. (2 mm). The Series
MULS can be used to monitor and control levels of water, chemicals,
lubricants, acids, or beverages in vessels, storage bins, or tanks.
The switch operates using ultrasonic sound wave propagation.
Ultrasonic sound waves are greatly attenuated when transmitted through
the air. Conversely, when a liquid is present, the transmission of the
sound waves is greatly enhanced. The unit generates electrical signals
that are converted to bursts of ultrasonic energy at the sensor. The
ultrasonic bursts are transmitted across the liquid sensing gap of the
sensor. Upon receipt of a valid signal at the receiver, the solid-stage
electronics generate a “data enable” condition indicating that a liquid is
present. The signal energizes a relay and provides an output condition.
INSTALLATION
The Series MULS level switch should be mounted within 15° of
horizontal. Make sure all wiring conforms to local and national electrical
codes.
Series MULS Miniature Ultrasonic Level Switch
Specifications - Installation and Operating Instructions
Bulletin L-38-MULS
SPECIFICATIONS
Service: Compatible liquids (non-coating, low viscosity).
Wetted Material: 316L SS.
Temperature Limits: -20 to 176°F (-29 to 80°C).
Pressure Limits: 250 psig (17.24 bar).
Enclosure Rating: General purpose.
Repeatability: ≤ .08˝ (2 mm).
Switch Type: SPST normally open dry relay, NPN transistor sink, or
PNP transistor source.
Electrical Rating: Relay: 1A @ 5-30 VDC, source & sink: 100mA.
Electrical Connections: 12˝ (304.8 mm) 5 conductor cable, 24 AWG
wire.
Leakage Current: Less than 50µA, sinking and sourcing.
Power Requirements: 5 to 30 VDC.
Process Connection: 1/4˝ or 1/2˝ male NPT.
Mounting Orientation: Within 15° of horizontal.
Delay: 0.5 seconds.
W.E. ANDERSON DIV., DWYER INSTRUMENTS, INC.
P.O. BOX 358 • MICHIGAN CITY, INDIANA 46360 U. S. A.
Phone: 219/879-8000 www.dwyer-inst.com
Fax: 219/872-9057 e-mail: info@dwyer-inst.com
1
HEX
[
25.4]
1/2 NPT
A
LARM
P
OINT
5/8
[15.88]
2-3/8
[60.33]
1
/4 NPT
ALARM
POINT
1-31/32
[50.2]
3/8
[9.53]
PRELIMINARY OPERATIONAL CHECK
Before installing the unit, a simple operation check should be performed
as follows:
1. Fill a container with a liquid.
2. Connect the power and control wiring cable to the electronic control
unit.
3. Apply power from the source.
4. Place the sensor in the liquid. The relay should energize.
5. Remove the sensor from the liquid. The relay will de-energize
indicating the system is functioning properly.
6. Disconnect the power to the unit.
7. Proceed to final installation if results were positive.
FINAL INSTALLATION
1. Drill a suitable hole in the vessel or pipe wall and tap for suitable NPT.
If this is a walled vessel or material is not suitable for threading, weld
or braze a bushing to accept the sensor.
2. Screw the sensor in the threaded section and make sure there is a
good seal. Use a pipe compound or sealing tape to avoid excessive
tightening. Do not over tighten.
3. Run the power and control wiring cable to the electronic control unit.
4. Connect the wires as shown in the diagram for the desired output
configuration.
Observe all applicable electrical codes and proper wiring
procedures.
MAINTENANCE
The electronics are constructed with solid-state components and are
epoxy potted. Periodically, check and clean the sensor when used with
liquids that cause a coating buildup on the sensor. No other maintenance
is required. A periodic check of the system calibration is recommended.
The Series MULS is not field serviceable and should be returned if repair
is needed (field repair should not be attempted and may void warranty).
Be sure to include a brief description of the problem plus any relevant
application notes. Contact customer service to receive a return goods
authorization number before shipping.
©Copyright 2013 Dwyer Instruments, Inc. Printed in U.S.A. 5/13 FR# R2-443575-00 Rev.2
W.E. ANDERSON DIV., DWYER INSTRUMENTS, INC.
P.O. BOX 358 • MICHIGAN CITY, INDIANA 46360 U. S. A.
Phone: 219/879-8000 www.dwyer-inst.com
Fax: 219/872-9057 e-mail: info@dwyer-inst.com
S
OURCE OUTPUT
SINK OUTPUT
+
5VDC-30VDC
C
HASSIS
G
ROUND
JUMPER WHITE WIRE
TO RED WIRED (+)
S
OURCE
G
ROUND (-)
RED
WHITE
B
ROWN
BLACK
GREEN
RED
WHITE
BROWN
BLACK
GREEN
+5VDC-30VDC
+5VDC-30VDC
SINK
GROUND (-)
CHASSIS
GROUND
CHASSIS
GROUND
JUMPER BROWN WIRE
TO BLACK WIRED (+)
RELAY OUTPUT
RED
BROWN
WHITE
BLACK
GREEN
GROUND (-)
RELAY
OUTPUT
/