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Environmental Water Products Division

High precision instruments, data logging & communications for effective water level measurement, flow control and environment management.

Echo TREK The Next Generation ultrasonic compact level transmitters

EchoTRECK the next generation ultrasonic compact level transmitters

The Next Generation compact ultrasonic liquid level transmitters.
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Automatic Tank Gauge / Purge Control

Level transmitters measure hydrostatic pressure using a simple air purge connection to the tank. An integral specialized airflow regulator ensures linear response throughout the entire operating range. Also available with integral containment barrier against release of liquids or vapors.

A downpipe is the simplest type of liquid level sensor, often referred to as
a “bubbler”. This is merely a length of open ended pipe that extends
downward into the tank. LiquiSeal™ or Purge Control differential pressure
air flow regulators are highly refined versions of the basic bubbler air
control.

Features

Continuous Level Measurement
Suitable for Corrosive or Aggressive Liquids
Pneumatic or Electronic (4-20 mA) OutputBiotech

Specifications

Specifications Electronic Transmitters

738 LiquiSeal D/P Purge Control
788 D/P Purge Control

Output
4-20 mAdc

Accuracy
0-5 psid trans./control ..... ±0.34% FS
0-10 psid trans./control ... ±0.27% FS
0-15 psid trans./control ... ±0.24% FS
0-30 psid trans./control ... ±0.22% FS
0-50 psid trans./control ... ±0.21% FS

Repeatability
± 0.02% of calibrated span

Maximum Depth Measurement
1,937 in. water (49 m water)

Specifications Pneumatic Transmitters

735 LiquiSeal Purge Control
780 Purge Control

Output
1:1 pneumatic pressure
(hydrostatic force equivalent)

Accuracy
± 0.009 psi (equivalent to ± 0.25 in.
of water depth)

Maximum Depth Measurement
3600 in. water (91 m water)*

Specifications All Models

Flow Rate (Air Purge)
Nominal 1 cfh (cubic foot per hour).

Compressed Air Requirement
35-150 psig supply pressure at control inlet. Set supply pressure at
least 20 psi greater than maximum liquid head pressure (but not less
than 35 psig).

Air Consumption
less than 5 cfh (< 0.08 scfm)

Temperature Range
0°F to 180°F/ -18°C to 82°C Actual process temperature limits
may be significantly higher, based on material used for downpipe and
purge airline.

* Requires nominal 150 psig
supply pressure at control inlet.

Download PDF brochure:

Download Purge Controls Brochure (222 kb)

automatic tank gauge atg

Purge Control

Features

Continuous Level Measurement
Suitable for Corrosive or Aggressive Liquids
Pneumatic or Electronic (4-20 mA) Output

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© 2001, 2002 Semrad Pty Ltd - The Level Control Company Australia
Australian distributor of level controllers, switches and transmitters,
designed specifically for harsh industrial applications,
including caustic and chemical solutions for liquid and solid measurement.