Hach 900 MAX manual Rain Gauge Programming, pH Probe Connection, Section

Section 5

5.1.1 Rain Gauge Programming

Note: When logging is enabled, an arrow will point to the logged channel.

1.From the Main Menu select OPTIONS>ADVANCED OPTIONS>DATALOG.

2.Highlight Select Inputs using the UP and DOWN keys and press SELECT.

3.Highlight Rainfall using the UP and DOWN keys and press SELECT.

4.Press the CHANGE CHOICE key to cycle between Logged and Not Logged, then press ACCEPT.

5.Enter a logging interval using the numeric keypad, then press ACCEPT. Valid logging intervals are shown on the status bar along the bottom edge of the display.

6.Select Rainfall Units (in. or cm).

7.Select another channel to configure, or press RETURN to back up one step. Press the MAIN MENU key to return to the Main Menu.

5.2 pH Probe

The pH probes are shipped with a wetting cap that covers the probe tip. Remove the cap by turning it counter-clockwise and gently easing it off. Keep this cap for long-term probe storage. Rinse the probe tip with distilled water.

Store the probe in a pH 4.0 buffer (Cat. No. 2104) for both overnight and long term storage. Never store a probe in distilled or deionized water because this will deplete the probe filling solution.

5.2.1 pH Probe Connection

This connector is for installing the pH or ORP pre-amp interface junction box or a stand-alone temperature sensor. The pH probe is attached to a terminal strip in the junction box. The stand-alone temperature probe plugs directly into the receptacle on the case.

The pre-amplifier junction box is provided to allow for fast, easy replacement of the pH probe.

Table 8 pH Connector Pin Assignments (J3)

Pin	Signal Description	Wire Color
A	+5 V dc	White
B	ground	Blue
C	reference	Yellow
D	pH/ORP	Black
E	-5 V dc	Red
F	RTD	Green

	Since the pH reading needs to compensate for temperature variation, a
	temperature sensor is built into every pH electrode. The pH probe consists of
	five wires, three for the pH probe and two for the temperature sensor.
	Stray electrical currents are sometimes found in wastewater stream. These
	stray electrical currents can affect the pH readings. In the case of stray
	electrical currents, a grounded pH probe is required. See Figure 22.
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pH Probe	8990options.fm