Hach 900 MAX manual Section, Enabling the Liquid Sensor

Section 3

b.If Stop After Last Sample is chosen, enter the samples to collect using the numeric keypad. Press ACCEPT to continue to Liquid Sensor.

11:00 AM 21 - APR - 01

SAMPLE DISTRIBUTION

ACCEPT

SAMPLES TO COLLECT:

2CLEAR

BACKUP

ENTRY

ENTER: 1 — 999

Example 1: The following example creates four identical composite samples automatically if the sampler is programmed as follows:

•Bottles— 4

•Sample Collection; Sampling Interval— 30 minutes

•Sample Collection; Samples to Collect— 25

•Sample Volume— 100 mL

Every 30 minutes a sample is initiated and a 100 mL sample is drawn into the first bottle. The distributor arm advances to bottle #2 and 100 mL of sample is drawn into the second. This also occurs in bottles #3 and #4.

Sampling will continue every 30 minutes until 25 samples are deposited.

Once all samples are deposited the program will terminate. If Run

Continuously is selected the sampling will restart automatically.

Step 7 - Liquid Sensor

The liquid sensor contains a pair of ultrasonic transducers which sense the presence of liquid inside silicone tubing.

7-A.Enable or Disable Liquid Sensor using the CHANGE CHOICE key.

Note: Sample retries cannot be enabled when the liquid sensor is disabled.

Enabling the Liquid Sensor

When the liquid sensor is enabled, the sampler will perform two duties:

•It senses when liquid reaches the pump during an intake cycle. The pump then reverses to rinse the line, up to three times.

•It senses the absence of liquid during a sample intake cycle if the intake tubing is plugged or if the water level has dropped below the level of the intake tube strainer. This initiates a Sample Retry if programmed

Disabling the Liquid Sensor/Timed Calibration

Disabling the liquid sensor turns the liquid sensor off. The sample volume is then metered using a timed method (Timed Calibration), instead of a sensed method.

7-B.Press ACCEPT to continue to Sample Volume.

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8990startup.fm	Basic Programming Setup