Tuesday, 31 May 2011 01:53 Last Updated on Monday, 29 August 2011 01:07 Written by Administrator

MODEL JH220: 2-WIRE TRANSMITTER
THERMOCOUPLE INPUT, FIXED RANGE, NONISOLATED

    • Available for All Thermocouple Types 
    • Input Ranges as low as 2mV
    • Low-Drift Input Amplifier
    • Fits Standard Connection Heads
    • -40 to +80 Degree C Operation
    • DIN Rail mounting available

    JH220
    PDF
    DATA SHEET

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.

ORDERING INFORMATION

Model Number: 

Model JH220.
Thermocouple Type:  

Specify type J, K, T, E, R, S, B or N, or contact factory for others.
Input Range: 

Specify any range corresponding to 2mVor higher span. (4mV equals approx. 50 deg. C for type K thermocouples.)
T/C Burnout Indication:  

(Always upscale – offscale high.)
Output Range: 

(Always 4/20mAdc.)
Power: 

(Always dc loop powered.)
DIN-Rail Mounting:  

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.)

DETAILED SPECIFICATIONS

Input Capabilities:  

Any input span 2mV or higher. Offset ranges are allowed.
Input Thermocouple Type:  

Any standard thermocouple type (J, K, T, E, R, S, B, N). Others possible –contact factory.
Thermocouple Burnout Indication:  

Output goes offscale high (above 20mA).
Output:  

4/20mA, 2-wire (loop-powered) output.
Accuracy (factory calibration): 

+/-0.1% of span or 10 microvolts, whichever is greater.
Adjustability: 

Zero and span each are adjustable approx. +/-15% of span.
Linearity: 

Linear with millivolts. Does not linearize the thermocouple.
Response Time: 

Under 100 milliseconds.
Guaranteed Operating Temperature: 

-40 to +80 deg. C (-40 to +176 deg. F).
Temperature Stability: 

+/-(0.02% of span plus 1 microvolt) per deg. C, or better.
Power Requirements: 

DC loop-powered. Requires at least 12Vdc at the transmitter’s output terminals. 36Vdc maximum.