Emerson Process Management 3081 pH/ORP Section Calibration of ORP Measurements, General

MODEL 3081 pH/ORP	SECTION 9.0
	CALIBRATION OF ORP MEASUREMENTS

SECTION 9.0

CALIBRATION OF ORP MEASUREMENTS

9.1General

9.2Entering and Leaving the Calibrate Menu

9.3Using the Hold Function

9.4Temperature Calibration

9.5Standardization

9.1 GENERAL

The Calibrate menu allows the user to calibrate the ORP and temperature response of the sensor.

The ORP calibration is a one-point standardization against an ORP standard. The temperature calibration is a one-point standardization against a reference thermometer. Prompts guide the user through the calibration proce- dures.

9.2. ENTERING AND LEAVING THE CALIBRATE MENU

Press CAL on the infrared remote controller (IRC) to enter the Calibrate menu. To store new settings in memory, press ENTER . To leave the Calibrate menu without storing new values, press EXIT . Pressing EXIT with a prompt showing returns the display to the first prompt in the sub-menu. Pressing EXIT a second time returns the transmitter to the process display.

If program settings are protected with a security code, pressing PROG or CAL will cause the Id screen to appear. Key in the security code and press ENTER . The first sub-menu will appear. For more information, see Section 5.7, Security.

A transmitter adjacent to the one being calibrated may pick up signals from the IRC. To avoid accidentally chang- ing settings, use a different security code for each nearby transmitter. See Section 5.7, Security, and Section 10.6, Display Units, for details.

9.3 USING THE HOLD FUNCTION

During calibration, the sensor may be exposed to solutions having an ORP outside the normal range of the process. To prevent false alarms and possible undesired operation of chemical dosing pumps, place the transmit- ter in hold during calibration. Activating HOLD keeps the transmitter output at the last value or sends the output to a previously determined value. See Section 10.3, Output Ranging, for details.

After calibration, reinstall the sensor in the process stream. Wait until readings have stabilized before deactivating Hold.

To activate or deactivate Hold, do the following:

1.Press HOLD on the IRC.

2.The HoLd prompt appears in the display. Press Ï or Ð to toggle the Hold function between On and OFF.

3.Press ENTER to save the setting.

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