Emerson 4500 manual Basic Setup, Set Process Variable Units, Rerange

Rosemount 4500

Reference Manual

00809-0100-4027, Rev AA December 2005

BASIC SETUP

Set Process Variable Units

Fast Keys 1, 3, 2

Rerange

The PV Unit command sets the process variable units to allow you to monitor your process using the appropriate units of measure.

HART Communicator

Enter the fast key sequence for “Set Process Variable Units.” Select from the following engineering units:

•	inH2O	•	bar	•	torr
•	inHg	•	mbar	•	atm
•	ftH2O	•	g/cm2	•	MPa
•	mmH2O	•	kg/cm2	• inH2O at 4 °C
•	mmHg	•	Pa	• mmH2O at 4 °C
•	psi	•	kPa

AMS

Right click on the device and select “Configuration Properties” from the menu. In the Basic Setup tab, use “Unit” drop down menu to select units.

The Range Values command sets the 4 and 20 mA points (lower and upper range values). In practice, you may reset the transmitter range values as often as necessary to reflect changing process conditions. Changing the lower or upper range point results in similar changes to the span.

NOTE

Transmitters are shipped from Rosemount Inc. fully calibrated per request or to the factory default of full scale (span = upper range limit.)

Use one of the methods below to rerange the transmitter. Each method is unique; examine all options closely before deciding which method works best for your process.

•Rerange with a HART Communicator only.

•Rerange with a pressure input source and a HART Communicator.

•Rerange with a pressure input source and the local zero and span buttons (option D1).

•Rerange with AMS only.

•Rerange with a pressure input source and AMS.

NOTE

If the transmitter security switch is ON, adjustments to the zero and span cannot be made. Refer to “Set Switches” on page 2-5for security information.

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