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Join Date: Sep 2009
Location: United Arab Emirates, Abu Dhabi
Posts: 50

Loop testing for a NON-HART 4 wire instrument

11/07/2009 9:00 AM

Hi Guys,

Need some guidance in as to how to carry out loop testing for a NON-HART 4 wire instrument ??? Any suggestions ???

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Anonymous Poster
#1

Re: Loop testing for a NON-HART 4 wire instrument

11/08/2009 2:43 AM

Input is insufficient

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Commentator

Join Date: Jun 2008
Location: Brick, NJ
Posts: 71
Good Answers: 8
#2

Re: Loop testing for a NON-HART 4 wire instrument

11/08/2009 7:35 AM

The loop testing procedure for a non-HART instrument isn't any different than for a HART instrument. The only thing that you might need to add is a 4-20 mA generator in place of the instrument to simulate the full range for testing your control system inputs, HMI, etc. Some non-HART instruments can do this from a menu internal to the instrument via a keypad so you don't even need the current transmitter.

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India - Member - Naveen Menon Engineering Fields - Instrumentation Engineering - Naveen Menon

Join Date: Oct 2007
Location: India
Posts: 92
Good Answers: 2
#3

Re: Loop testing for a NON-HART 4 wire instrument

11/09/2009 4:02 AM

Depends on the circuit. Say its a loop powered inst then may be a resistor of the right ohms in place of the inst will do.

v=ir ..

if its not a loop powered and then you might need to use a 4-20mA generator in place of the instrument,

Hope this helps.

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Commentator

Join Date: Jun 2008
Location: Brick, NJ
Posts: 71
Good Answers: 8
#4
In reply to #3

Re: Loop testing for a NON-HART 4 wire instrument

11/09/2009 6:14 AM

The OP stated that it was a 4-wire instrument so it isn't loop powered.

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