Ametek Drexelbrook Impulse GW Series, Installation And Operating Instructions Manual

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Introduction
1
Section 1
Section
1
: Introduction
1.1 Product Overview
The 2-Wire Impulse® TDR Level Measurement System (LMS)
The Impulse Level Measurement System is designed to measure the
distance, level and volume of liquids and slurries. It can be operated on
storage and process vessels.
The Impulse LMS is comprised of:
• The 2-wire electronic signal converter or Modbus digital output module
• The sensor system
The signal converter can be removed from the sensor system under
process conditions, without loss of pressure or exposure to the process
material.
Impulse TDR Technology:
In Time Domain Reflectometry (TDR) a high frequency pulse is generated
and transmitted along the sensor. Discontinuities caused by changes in the
electrical properties of the medium through which the pulse is travelling
or tank structures within the pulse area will produce reflections which
are detected by the electronics. The time between the pulse transmission
and reflection detection times the velocity of the pulse divided by 2 will
equal the distance to the product surface [d = (t2-t1)v/2].
Impulse TDR Technology:
Coaxial
7/8” (22 mm)
OD
Single rod/cable
12” min.
(305 mm)
4” min.
(100 mm)
2” min.
(51 mm)
ground rod
(welded to mounting)
Dual rod/cable
Figure 1 Sensor pulse width