The Model JH220 2-wire transmitter provides a 4/20mA current loop output proportional to the input from a thermocouple. A fixed-range device, it is precisely calibrated to your specified input range at the factory. (For a rangeable 2-wire thermocouple transmitter see Model JH225.) Span may be as low as 2 millivolts (approximately 50 deg C for type K thermocouple). Cold junction compensation is located in the terminal block for optimum accuracy. Conformal coating protects the circuitry against condensation and corrosion in industrial atmospheres. Upscale burnout indication is standard.
The JH220 is a loop-powered device. Connected in series between a 24Vdc supply and readout instruments, it receives its power from the 4/20mA output loop. A built-in LED indicates loop current: dim at 4mA, bright at 20mA. The JH220 does not provide input/output isolation.
Specify type J, K, T, E, R, S, B or N, or contact factory for others.
Specify any range corresponding to 2mVor higher span. (4mV equals approx. 50 deg. C for type K thermocouples.)
(Always upscale – offscale high.)
(Always dc loop powered.)
Change model number to Model JH220-DIN. (See "Installation and Connections," below.)
INSTALLATION AND CONNECTIONS
The JH220 is 1-3/4 inches in diameter and is designed to fit many standard thermocouple-type connection heads. It may also be mounted to any surface using two #8 (or smaller) screws. An optional DIN-rail mounting clip (specify Model JH220-DIN) allows the transmitter to be snapped onto DIN rail. Width is 1-3/4 inches.
Connections are made to the transmitter’s terminal strip. Connections are:
"+" Terminal: Output/Power Loop. Receives current from (+) DC supply.
"-" Terminal: Output/Power Loop. Passes on current to the next series loop device, or to the (-) supply.
Terminal A: Thermocouple plus.
Terminal B: No connection – compensator is encapsulated in this position.
Terminal C: Thermocouple minus. (On most thermocouples, the red wire is minus.)
Any input span 2mV or higher. Offset ranges are allowed.
Any standard thermocouple type (J, K, T, E, R, S, B, N). Others possible –contact factory.
Output goes offscale high (above 20mA).
4/20mA, 2-wire (loop-powered) output.
+/-0.1% of span or 10 microvolts, whichever is greater.
Zero and span each are adjustable approx. +/-15% of span.
Linear with millivolts. Does not linearize the thermocouple.
Under 100 milliseconds.
-40 to +80 deg. C (-40 to +176 deg. F).
+/-(0.02% of span plus 1 microvolt) per deg. C, or better.
DC loop-powered. Requires at least 12Vdc at the transmitter’s output terminals. 36Vdc maximum.