GENERAL DESCRIPTION
The Apollo Intelligent RTD Meter (IMR) accepts standard RTD inputs and
precisely linearizes them into temperature readings. A full 6-digit display
accommodates a wide range of temperature inputs and holds large totalization
values. State-of-the-art digital circuitry virtually eliminates errors due to drift. A full
complement of option packages is available to fulfill many process applications.
TheindicatorfeaturesareadoutchoiceofeitherFahrenheitorCelsiuswith0.1
or 1 degree of resolution. English Style display prompts aid the operator through
set-up and operation. A front panel lock-out menu protects set-up data and
operation modes from unauthorized personnel. Programmable digital filtering
enhancesthestabilityofthereading.Programmableremoteinput“E1-CON” pin
can be utilized to control a variety of functions, such as totalizing, alarmcontrol,
peak/valleyreading,display holdoroffset operations.Allset-up data isstoredin
E2PROM, which will hold data for a minimum of 10 years without power.
Anoptionalintegrator/totalizercan be used to totalizeorintegrate temperatures
up to a maximum display value of 999,999. It features independent scaling and a
low temperature cut-out to suit a wide variety of temperature integration
applications. Programmable remote input “E2-CON” pin is included with the
optionand canbeutilizedtocontrolavarietyoffunctions,suchastotalizing,alarm
control, peak/valley readings, display hold or offset operations, simultaneously
with “E1-CON” pin. Peak/valley (max/min) reading memory functions are
included with this option and they are easily recalled and controlled by either the
front panel or a remote input. All readings are retained at power-down.
Optional dual relays with parallel solid state outputs are fully programmable
tooperateinawidevarietyofmodestosuitmanycontroloralarmapplications.
Optional 20 mA loop, bi-directional serial communications provides
computer and printer interfacing to extend the capabilities of the indicator.More
than one unit can be connected in the loop with other RLC products which have
serial communications capabilities.
An optional 4 to 20 mA or 0 to 10 VDC re-transmitted analog output can be
scaledbytheuserto interfacewitha hostof recorders,indicatorsand controllers.
The type of analog output is determined by the Model No. that is ordered. (See
Ordering Information for available models.) The indicator has several built-in
diagnosticfunctions toalert operatorsof mostmalfunctions.Extensivetesting of
noise interference mechanisms and full burn-in make the indicator extremely
reliableinindustrialenvironments.Thedie-castfrontbezelmeetsNEMA4/IP65
requirements for washdown applications, when properly installed. Plug-in style
terminal blocks simplify installation wiring and change-outs.
THEORY OF OPERATION
TheIMRemploysa microprocessorto performtheA/D conversiononthe input
signal via a voltage-to-frequency converter. It digitally scales the result, corrects
formeterdrift whichmaybepresentandthendisplaysthe resultina6-digitdisplay
(4 digits for temperature, 6 digits for totalizer). The inputs are filtered to enhance
the stability of the display. A non-volatile E2PROM memory device provides
permanent data retention for operating variables. The display consists of drivers
and 6-digit solid-state LEDs. The alarm option employs opto-isolators to isolate
the open collector devices from meter common. Operating in parallel, the relays
aretypeForm-Cand areratedat5-amps.Theserialcommunicationoption features
a built-in 20 mA current source and complete opto-isolation. The analog option
features a 12-bit DAC and provides an output signal that is digitally scaled. The
re-transmitted output is isolated from meter common.
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