rosemount absolute xmtr.

6 comments

Rate

speedtron Associate Join Date: Mar 2009 Posts: 33	rosemount absolute xmtr. 04/05/2009 8:09 AM
	Chief, How to calibrate rosemount 3051 absolute xmtr 0-100bar. 4-20mA our absolute druck pdi 610 cannot reach to 0 bar absolute press..the lowest we get is 2.5 bar 4.791 mA. and the absolute pressure here is 0.987 bar. absolute. when we change the range LRV , URV message come exceed precision. why we can not change the range. what we did is subract the absolute press. 0.987bar to 100bar. and we trim the URV to 20mA. so 99.013 bar equals to 20mA. this kind of calibration is how many percent correct.or error. what is other solution for that, what kind of instrument,brand we can use to reach the 0 absolute pressure. and why the connection supply of this absolute pressure xmtr.is connected DIRECT to the natural gas Pipe with morethan 500psi. not in the atmosphere. regards, speed
	Register to Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Doggoneit Power-User Join Date: Oct 2007 Location: Canning Vale Western Australia. Posts: 160 Good Answers: 7	#1 Re: rosemount absolute xmtr. 04/06/2009 7:45 PM
	Most calibrations require at least a 2 point calibration to check correct calibration. However these points do not need to be the end points. Calculate the expected milliamp output for say 5 bar and then check it at that point, then do the 100 bar. Leave your LRV and URV at 0 and 100 bar. This will give you the correct readings. __________________ I attend work so my dogs can have the good life.
	Register to Reply

speedtron Associate Join Date: Mar 2009 Posts: 33	#2 In reply to #1 Re: rosemount absolute xmtr. 04/06/2009 9:34 PM
	Chief Doggoneit, Thanks. Regards, speed
	Register to Reply

Anonymous Poster	#3 Re: rosemount absolute xmtr. 04/06/2009 10:38 PM
	If the transmitter is scaled with a span from 0 to 100 bar, then each unit is equal to .16 millamps. 2.5 bar would equal 4.4 milliamps, and 99.013 would equal 19.84 milliamps.Most calibration procedures call for calibration at 20 percent and 80 percent of span. So that would be 20 bar equals 12 millamps, and 80 bar equals 16 milliamps. Does this help?
	Register to Reply

Vulcan Guru Join Date: Oct 2006 Location: Northern Mindanao, Philippines Posts: 2147 Good Answers: 53	#4 Re: rosemount absolute xmtr. 04/07/2009 8:57 AM
	I've never heard of a 0 to 100 bar absolute pressure transmitter but we use several 0 to 1.00 bar absolute transmitters. Are you sure it's 100 bar? Anyway, I once contacted Foxboro because we had the same problem as you. There was no way for us to reach 0 bara (bar absolute). They suggested us to rerange the transmitter to 0 to 1 barg (bar gauge). So we just zero at atmospheric pressure then inject with 1 barg and span. Then we rerange the transmitter back to 0 to 1 bara. We needed to compensate for altitude but we don't need to adjust very much since the factory is close to the sea anyway. regards, Vulcan __________________ Miscommunication: when what people heard you say differs from what you said. Make yourself understood.
	Register to Reply

speedtron Associate Join Date: Mar 2009 Posts: 33	#5 In reply to #4 Re: rosemount absolute xmtr. 04/07/2009 1:09 PM
	Chief Vulcan, Thanks,yes its 0-100Bar A. and its writen on device summary. and the atmopsheric pressure here now is 1.014Bar. What we did is take the atm. press. and subtract to 100Bar. (.987 bar atm.press. - 100 bar.) 99.013 bar = 20.0004 mA 74.013 bar =16.003 mA 49.013 bar = 12.0002 mA 24.013 bar = 8.0002 mA 2.5 bar = 4. something because we cannot reach to zero absolute pressure. Yes i was confuse also,why they use this kind of transmitter and its connected to the natural gas pipe line.not in the atmospher,. not the same with the others 22inHg to 37inHg 4-20mA Absolute. and the tubing goes to atm.for this device no problem and no confusion. Thanks, speed
	Register to Reply

naveen_menon Commentator Join Date: Oct 2007 Location: India Posts: 92 Good Answers: 2	#6 Re: rosemount absolute xmtr. 04/10/2009 5:45 AM
	Could you please tell what model is it 3051TG or something like that.
	Register to Reply

Copy to Clipboard

Anonymous Poster (1); Doggoneit (1); naveen_menon (1); speedtron (2); Vulcan (1)

You might be interested in: Bar Code Software, Absolute Rotary Encoders, Bar Code Cards

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (58 right now) Show Members