Emerson Process Management 3081 pH/ORP Section Maintenance, Overview, Transmitter Maintenance

MODEL 3081 pH/ORP	SECTION 11.0
	MAINTENANCE

SECTION 11.0

MAINTENANCE

11.1Overview

11.2Transmitter Maintenance

11.3pH Sensor Maintenance

11.4ORP Sensor Maintenance

11.5Calibration

11.1 OVERVIEW

This section gives general procedures for routine maintenance of the 3081 pH/ORP transmitter and pH and ORP sensors. The transmitter needs almost no routine maintenance. Sensors require periodic inspection and cleaning. The calibration of the transmitter-sensor combination should be checked regularly, and the loop recalibrated if necessary.

11.2 TRANSMITTER MAINTENANCE

Periodically clean the transmitter window with household ammonia or glass cleaner. The detector for the infrared remote controller is located behind the window at the top of the transmitter face. The window in front of the detec- tor must be kept clean.

Most components of the transmitter are replaceable. Refer to Figure 11-1 and Table 11-1 for parts and part numbers.

FIGURE 11-1. Exploded View of Model 3081 pH/ORP Transmitter

Three screws (part 13 in the drawing) hold the three circuit boards in place. Removing the screws allows the display board (part 2) and the CPU board (part 3) to be easily removed. A ribbon cable connects the boards. The cable plugs into the CPU board and is permanently attached to the display board. A 16 pin and socket connector holds the CPU and analog (part 4) boards together. Five screws hold the terminal block (part 5) to the center housing (part 7), and the 16 pins on the terminal block mate with 16 sockets on the back side of the analog board. Use caution when separat- ing the terminal block from the analog board. The pin and socket connection is tight.

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