Hach SP-510, Instrument Manual

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SECTION 4 OPERATION
4.1 Instrument Operation
After the instrument is installed on line, the only operator requirements are
replenishing buffer and indicator reagents (at approximately two-month intervals)
and standardizing the instrument. The instrument is designed to function operator-
free for a minimum of two months. Periodically run a visual check to become
aware of any problems such as bubbles in the tubing that would indicate an air
leak. Be sure the colorimeter plugs are in place.
On power-up, the green LED (SOFT) will flash. It will continue to flash until the
first reading is obtained. Each cycle takes two minutes. As long as the hardness of
the sample is below the alarm point value of the selected reagent, the SOFT
indicator will be illuminated. The HARD indicator will light only when the
sample-reagent mixture measurement exceeds the trip point for two successive
measurements. The alarm circuit relay will actuate and the HARD indictor will
light. Pressing
ALARM OFF
will deactivate the alarm relay. The ALARM OFF
indicator will be illuminated when the alarm relay is deactivated.