Hach 900 MAX ユーザーズマニュアル

8990int.fm

The sampler is designed for indoor, permanent installation. All controls are 
located on the front panel. Capped, watertight connectors for interfacing to 
external devices are located along the left side of the controller.

The sampler uses a liquid sensing system to detect the absence or presence 
of liquid at the peristaltic pump intake. The liquid sensor (

) is located 

on the front of the control housing.

The liquid sensing system provides three primary benefits:

Accurate, repeatable sample volumes

Intake tube prerinse 

Sample retry

Accurate, Repeatable Sample Volumes
The liquid sensor detects the presence and velocity of the incoming sample. 
This information allows the sampler to automatically dispense the correct 
amount of liquid into the sample bottle. 

The liquid sensing system allows the sampler to deliver repeatable sample 
volumes even with changing suction lifts. Each time the peristaltic pump pulls 
a sample, the microprocessor determines the time required for liquid to travel 
to the liquid sensor. If the suction lift increases due to a drop in level at the 
sample source, the time required for liquid to reach the sensor will increase. 
The microprocessor automatically compensates for this change by allowing 
the peristaltic pump to deliver sample liquid for a corresponding longer period 
of time. Conversely, if suction lift decreases due to an increase in level at the 
sample source, the time required for liquid to the sensor will decrease. Again, 
the microprocessor automatically compensates for this change by decreasing 
the sample delivery time. 

Sensor Body

Sensor Cover

Knobs (turn to remove)

2

1

3