AMETEK 7230 HT Digital Probe - Manual (Page 4)

2
Permanent
Magnet
Interrogation Pulse
Patented
Reflector
t
1
t
2 (continued)
t
2
Magnetostrictive Wire
Magnetostrictive Principle
1. A high current interrogational pulse creates an
electromagnetic fi eld along the magnetostrictive
wire.
2. Interaction with the permanent magnet creates a
torsional strain pulse that travels up (t
1
) and down
(t
2
) the wire.
3. The torsional strain pulse travels up the wire to a
small pick up sensor at the top of the transducer.
The pulse traveling down the wire is refl ected and
continues up the wire to be sensed by the same
pick up sensor.
4. The time between the pulse (t
1
) and the pulse (t
2
)
is used to determine the level.
The 7230 Series HT Digital Probe is a new
magnetostrictive level measurement system from
AMETEK APT for the up-stream Oil & Gas Industry
and high temperature applications that require multiple
level and temperature measurements.
Magnetostrictive level measurement technology has
the capability of providing the highest accuracy of
any of the most popular level technologies that are
currently offered in today’s market. The 7230 Series is
no exception, as it exceeds the high accuracy of the
proven 7330 Series with an impressive accuracy of
0.01% of measured span.
The 7230 HT Digital Stik is a level measurement
solution that provides both total level, interface level
and up to 5 temperature readings that requires only
one process connection. The 7230 Series has multiple
output options, a digital ASCII interface and an RS-485
Modbus RTU digital output with an optional analog
interface. The 7230 Series is approved as Explosion
Proof (without Intrinsic Safety Barriers) for Class I, Div.
1, and Zone 1 hazardous area installations.
The advantages of magnetostrictive technology
include high accuracy and reliable level measurement
capabilities that are completely independent
of changes in the process material’s electrical
characteristics and densities. Hydrocarbon based
condensates have a predictable range of specifi c
gravity that are well within the range of fl oats that are
part of this product offering. There is no calibration
required to set up the probe. Variations in hydrocarbon
make up will not cause any level measurement errors.
A choice of two communication protocols are available.
The 7231 HT has a patented Modbus module that
provide 12 Register Maps using 16 or 32 bits, with
either Modbus RTU or ASCII transmission. In
addition, there is an optional Analog output converter
available for 4-20mA applications. The 7235 HT
has a proprietary ASCII digital output and would be
recommended for OEM use. The new sensor has
an explosion proof approval for use in Class I, Div. I,
Group A, B, C, and D hazardous area installations.
The advantages of magnetostrictive technology
include high accuracy and repeatability, plus reliable
level measurement capabilities that are completely
independent of the process materials electrical
characteristics. The standard fl oat is suitable for most
liquids with a minimum density of 0.5 specifi c gravity.
Section 1 - 7230 Series HT Digital Probe