Filter
Top Products
GENERAL DESCRIPTION
The Apollo Intelligent ThermistorMeter (IMY)accepts standard Thermistor
inputs and precisely linearizes them into temperature readings. Like an RTD, a
thermistorisatemperaturesensitiveresistor, butthethermistorprovidesamuch
largerresistance changeper degree.Sincethermistors providealargeresistance
change, significant errors from long lead lengths or switches are eliminated.
Other advantages of using a thermistor are accuracy, repeatability, long term
stability, and sensor cost. 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.
The IMY supports two popular thermistor series - the 400 Series 2,252
Ohm thermistor, and the 700 Series Thermolinearä thermistor. Selection
between the two types is done in Programming Module #1.
TheindicatorfeaturesareadoutchoiceofeitherFahrenheitorCelsiuswith
0.1 or 1 degree of resolution. English Styledisplay 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 enhances the stability of the reading. Programmable remote
input“E1-CON” pincan beutilized to controla varietyof functions,such as
totalizing, alarm control, peak/valley reading, display hold or offset
operations.Allset-updataisstoredintheE
2
PROM,whichwillholddatafora
minimum of 10 years without power.
An optional integrator/totalizer can be used to totalize or integrate
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. A programmable remote input,
“E2-CON”,isincludedwiththeoptionandcanbeutilizedtocontrolavariety
of functions, such astotalizing, alarm control, peak/valley readings, display
hold or offset operations, simultaneously with the “E1-CON”. Peak/valley
(max/min) reading memory functions are included with this option and they
are easily recalled and controlledby eitherthe frontpanel ora remoteinput.
All readings are retained at power-down.
Optionaldualrelayswithparallelsolidstateoutputsarefullyprogrammable
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.
Anoptional4to20mAor0to10VDCre-transmittedanalogoutputcanbe
scaled by the user to interface with a host of recorders, indicators and
controllers. The type of analog output is determined by the model ordered.
(See Ordering Information for available models.)
Theindicatorhasseveral built-indiagnosticfunctionsto alertoperatorsof
most malfunctions. Extensive testing of noise interference mechanisms and
fullburn-inmaketheindicatorextremelyreliableinindustrialenvironments.
The die-cast front bezel meets NEMA 4/IP65 requirements for washdown
applications. Plug-in style terminal blocks simplify installation wiring and
change-outs.
THEORY OF OPERATION
TheIMY employs amicroprocessor toperform theA/D conversion onthe
input signal via a voltage-to-frequency converter. It digitally scales the
result, corrects for meter drift which may be present and then displays the
resultina6-digitdisplay(4digitsfortemperature,6digitsfortotalizer).The
inputs are filtered to enhance the stability of the display. A non-volatile
E
2
PROM 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 are type Form-C and are rated at
5-amps. The serial communication option features a built-in 20 mA current
sourceandcompleteopto-isolation.Theanalogoptionfeaturesa12-bitDAC
and providesa4to20mAor0to10VDCoutput thatis digitally scaled. The
analog output is isolated from meter common.
-4-