Chemical Engineering November 2012 - 21

Brooks Instrument
FIGURE 3. Brooks SolidSense II ATEX industrial pressure transmitters use glassfused
strain gauge technology, which enables high performance in industrial
applications
tion back and forth with operations for
additional directions, " explains Dimm.
A maintenance mode indication
was also added to the SmartLine devices.
When used in conjunction with
Honeywell's Experion PKS (Figure
1), both operators and the network
can advise the transmitter when the
loop is in a mode that is safe for maintenance.
" This means in addition to
knowing that it's the right instrument
and what actions he should take, he
also knows whether the transmitter
is available for maintenance, " says
Dimm. " The combined display technology
and maintenance-mode indication
features eliminate tripping alarms
and increase efficiency and maintenance
safety, as well as the efficiency
and safety of the entire plant. "
Record keeping
Following tougher regulations regarding
the documentation of mandatory
safety tests, processors - especially
those in the oil and gas industry -
are seeking pressure measurement
instrumentation that makes it easier
to record and document actions.
In the past, standard chart recorders
might have been used, but because
they are mechanical devices, it is not
easy to get recorded information into
an electronic format that can be easily
emailed or electronically delivered
from one place to another.
So, Crystal Engineering (San
Luis Obispo, Calif.; www.crystal
engineeroing.net) developed the nVision,
reference pressure recorder
(Figure 2). " This is a reference-class
recording device, meaning it provides
high-accuracy readings, that delivers
high-speed recording capability
and can be used as a troubleshooting
device to aid in efficiency and maintenance, "
says Jim Pronge, sales manager
with Crystal Engineering.
The device is portable enough to
allow complete calibration anywhere
and is accurate enough to replace a
deadweight tester. This is a gage/absolute
pressure datalogger to 15,000
psi and offers differential pressure
with up to 0.025% of reading accuracy.
And, it displays live data graphically
without a PC, but can connect to a PC
to view live readings or export tamperproof
digital recordings.
Accuracy and stability
Pressure transmitters are widely used
in high-purity and ultra-high-purity
fluid storage and delivery systems.
Unfortunately, a number of current
transducers rely on technologies that
have problems with zero and span
drift, thermal shift and case stress.
Adjusting the pressure transmitter to
rectify errors requires ongoing maintenance
that increases downtime and
cost of ownership. However, a combination
of optimum design and materials
can improve both signal stability and
reliability, says Ken Tinsley, director
of pressure and vacuum measurement
with Brooks Instrument (Hatfield, Pa.;
www.brooksinstrument.com).
For example, Brooks' SolidSense
II industrial pressure transmitters
(Figure 3) use glass-fused strain
gauge technology, which enables a
new level of performance. The micromachined
strain gauges are matched
and fused to the metal diaphragm at
high temperature to relieve manufacturing-induced
stress. This process
reduces drift or lack of zero stability
commonly associated with most pressure
transmitters.
And the XacTorr CMS capacitance
manometers for process vacuum measurement
include premium, heated
gauges that use dual-zone heating to
ensure temperature uniformity. The
device's electronics are temperature
compensated to minimize drift due to
ambient temperature changes.
An important benefit of this manometer
is its Mark-IV sensor, which
has a chamber that contains surface
areas that are not used in pressure
measurement. These surfaces provide
locations for particles and condensable
vapors to accumulate without affecting
the sensor, reducing the need for
re-zeroing and extending sensor life. ❏
PRESSURE
MEASUREMENT
PRODUCTS
Smart barrel transmitter
provides small footprint
Used for shale oil-and-gas applications,
the TX200H HART smart pressure
transmitter provides a small
footprint. Using the latest HART 7
specifications, it reliably communicates
asset management data while
providing simplified field adjustment.
A flexible 10:1 turndown on the pressure
ranges from 0 to 15 psi up to 0 to
25,000 psi and allows the transmitters
to be ranged as needed to meet user
requirements. The transmitter is constructed
of 316 stainless steel, welded
and hermetically sealed to meet enclosure
type 4X and IP66 requirements.
It can be mounted directly onto the
process or panel mounted within the
control panel. - United Electric Controls
Co., Watertown, Mass.
www.ueonline.com
This pressure indicator offers
precision and stability
The PACE 1000 pressure indicator,
modular pressure instrument for rack
mounting, test bench or bench top applications
is available in three grades
of precision performance, and a choice
CHEMICAL ENGINEERING WWW.CHE.COM NOVEMBER 2012 21
http://www.ueonline.com http://www.brooksinstrument.com http://www.crystal http://www.engineeroing.net http://WWW.CHE.COM
Chemical Engineering November 2012

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