910-A1A0-003 Datasheet, PDF (2/4 Pages) Magnetrol International, Inc. – Echotel® Model 910 Ultrasonic Level Switch

TECHNOLOGY
The Model 910 Level Switch uses ultrasonic energy to
detect the presence or absence of liquid in a 316 SS tip
sensitive transducer gap. The basic principle behind
ultrasonic contact technology is that high-frequency
sound waves are easily transmitted across a transducer
gap in the presence of a liquid medium, but are
severely attenuated when the gap is dry. The Model
910 uses an ultrasonic frequency of 3 MHz to perform
this liquid level measurement in a wide variety of
process media and application conditions.
The transducer uses a pair of piezoelectric crystals that
are encapsulated in epoxy at the tip of the transducer.
The crystals are made of a ceramic material, such as
lead zirconate. The transmit crystal converts an electri-
cal signal from the Model 910 electronics into an ultra-
sonic signal. When liquid is present in the gap, the
receive crystal is able to sense the ultrasonic signal
from the transmit crystal and convert it back to an elec-
trical signal. This signal is sent to the electronics to
indicate the presence of liquid in the transducer gap.
When there is no liquid present, the ultrasonic signal is
attenuated, and the receive crystal is not able to sense
the sound waves from the transmit crystal.
High alarm
Low alarm
Ultrasonic
transducer
Transmit
crystal
Receive
crystal
Ultrasonic signal transmission
across transducer gap
High alarm
Low alarm
Filling line
Pump protection
Pump
Typical applications and mounting positions
ELECTRICAL SPECIFICATIONS
Power Supply:
Power Consumption:
Relay Output:
Repeatability:
Fail-safe:
Calibration:
Ambient Temperature:
Process Temperature:
Shock:
Vibration:
Operating/Non-Operating Pressure:
120 VAC (+10%/-15%), 50/60 Hz
240 VAC (+10%/-15%), 50/60 Hz
24 VDC (±10%)
2.5 VA nominal
Gold flash DPDTŒ: 10 amps @ 120 VAC, 10 amps @ 240 VAC
10 amps @ 24 VDC, 0.5 amps @ 125 VDC
Hermetically sealed DPDT: 5 amps @ 120 VAC, 3 amps @ 240 VAC
5 amps @ 24 VDC
0.078" (2 mm)
Field selectable high or low
None required
Electronics: -40° to +158° F (-40° to +70° C)
Transducer: -40° to +250° F (-40° to +121° C)
ANSI/ISA-S71.03 Class SA1
ANSI/ISA-S71.03 Class VC2
800/1500 psig (55/103 bar)
ΠGold flash DPDT relay is rated at 8 amps when used with housing codes 5 or P
2