Hach 900 MAX manual Submerged Pressure Sensor Connection, Section

Section 4

Note: Always check the Level Adjust when reinstalling the sampler following a calibration. (See Keypad Description on page 16.)

3.Place the sensor face up in the bucket or liquid. Tap lightly to remove air bubbles. If these bubbles are not removed you can receive false readings from the sensor during calibration (Figure 17).

4.Place the sensor face down under at least 16 cm (6 in.) of water and wait 20 seconds. Make sure the water surface is calm and the sensor is stable.

5.Press any key to continue.

6.Measure the depth from the bottom of the bucket to the surface of the water and enter the value using the numeric keypad (Figure 17).

7.Press ACCEPT.

Figure 17 Calibrating the Submerged Area/Velocity Sensor

4.3 Submerged Pressure Sensor

The submerged pressure sensor is a pressure transducer that contains a titanium diaphragm. As the water pressure increases, (with increasing level in the flow stream) the diaphragm is deflected, or pushed, against a solid state device called a strain gauge. The strain gauge converts the pressure against the diaphragm to a voltage. As the level in the flow stream increases, the voltage coming from the submerged pressure sensor increases. The voltage is read by the microprocessor in the Sampler at a regular interval and converted to a number which represents the level in the flow stream. The level reading can then be converted by the meter to a flow rate based on the mathematical formula for the selected primary device.

4.3.1 Submerged Pressure Sensor Connection

The submerged pressure sensor connection is located on the left side of the controller housing and is labeled submerged pressure sensor. The connector is keyed and can only be inserted in the proper orientation (key up).

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