Existing gauge systems may be updated to take advantage of todays technology while maintaining
the confidence in a system has proven itself over time. Retrofitting digital equipment to
bubbler type gauge systems that have been in service from 20 to 30 years is quite common.
Retrofit systems also serve as a backup for other existing gauges and allow users to compare
readings from the same tank to assure accuracy. Installation is very simple using existing
air line and pressure pipe. They may be installed while the tank is in service.
Retrofit Digital Tank-O-Meters® are also supplied with new type
"S" Tank-O-Meters®. Transducers can be conveniently factory
mounted on the type "S" gauge to make field connection as simple as
"plugging-in".
Level setpoints to warn of impending spills; activation of other controls; signal outputs for
data acquistion and displaying the tank content either locally or at a remote location are
simultaneously added by a Retrofit Digital Tank-O-Meter®. An existing system
can remain fully operational as before.
"Retrofit Local" Digital Tank-O-Meter® for
mounting locally within a few feet of an existing Uehling gauge or other pressure sensing system.
(This system uses the Bubbling Bottle or Tel-Flo meter mounted on the existing gauge for
pneumatic signal reading). Retrofit Local systems are designated by adding the letters
"RL" prior to the model number -- e.g. RR-10VV.
"Retrofit Remote" Digital Tank-O-Meter® is
mounted remotely and attached to an existing Uehling gauge or other pressure sensing system
(a pneumatic signal reading second gauge location with it's own Bubbling Bottle or Tel-Flo
meter). This system requires its own Bubbling Bottle or Tel-Flo meter at the digital display
location to assure the operator that the system is functioning. Retrofit Remote systems
are designated by adding the letters "RR" prior to the model number -- e.g. RL-10VV.
Single or multiple systems can be factory mounted together with alarms control relays and
additional setpoints. Wall mount enclosures are supplied fully wired with terminal block
connections.
Enclosures simplify field mounting, save time on planning installation and are a convenient
way to mount gauges and alarms at a central location as well as additional (Dual Displays)
locations. A variety of wall or panel mount enclosures are available for NEMA 1 General
Purpose. NEMA 4 (4X) Watertight and NEMA 7 Explosion proof locations.
16 bit resolution (65,536 segments) for repeatable, precise measurement
Accuracy and resolution directly affect measurement precision. Digital systems combine
pressure transducer's infinite resolution with a signal processor's defined resolution
characteristics.
Pressure transducer accuracies are generally expressed as a percentage of full scale and
their resolution is infinite. On the other hand, digital displays, signal conditioners, PC's
etc., have dramatically better accuracies but have limited internal resolution that divides
the transducer's full scale signal into parts. High resolution enhanced the capability to
more precisely view changes in the tank depth, volume or weight.
It can be misleading to express accuracy as a percentage of full scale when .05%, .1%, .15% or
.25% could represent a fraction of an inch as easily as a foot of liquid depth. For liquid
level purposes, it is more meaningful to express full scale accuracy as a function of tank
depth. Moreover, it is usually more important to precisely measure a change in level. This
is where resolution plays a crucial role.
For example, suppose a tank is full and the liquid level is lowered from 20 to 15 feet. Could
we control and measure it precisely to within 1/32 inch? The answer is yes. 1/32 inch
(.03125) is one part in 7680 (20 feet = 240 inches x 32 parts per inch = 7680); this is well
within the 16 bit Uehling system resolution where one least significant bit (LSB) corresponds
to less than .004 inch resolution.
Consider additionally that the volume or weight per inch of depth is a major variable depending
on the tank shape and dimensions. Resolution is especially significant when small changes in
tank depth are equivalent to many Gallons, Pounds, Liters or other unit of measure.Retrofit System
Enclosed Digital Tank-O-Meter®
Accuracy & Resolution
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