Section 2 General Information; Instrument Description; Interface Connectors; Receptacle Caps - Hach SIGMA 900 Instrument Manual

Section 2

2.1 Instrument Description

2.2 Interface Connectors

2.2.1 Receptacle Caps

8544intro.fm
General Information
The instrument is designed to automatically collect and preserve samples
from a liquid source. The sampler is suitable for collection of conventional and
toxic pollutants and suspended solids.
The sampler collects samples on either a timed cycle basis, or in proportion to
flow when used in conjunction with a flow meter (flow meter connected to the
auxiliary connector). In the timed cycle mode, the interval between samples is
controlled by an integral quartz crystal clock. The sample interval may be set
from 1 to 9999 minutes, in one minute increments.
In the flow proportional mode, via an external flow meter, the interval between
samples may be set from 1 to 9999 flow pulses, in one pulse increments.
where each pulse represents a specific flow volume interval.
The number of minutes or flow intervals remaining unit the next sample is
shown on the control display. The program can be delayed by entering the
desired starting time and date on the sampler keypad.
The sampler utilizes a high speed peristaltic pump, for collection of the
sample liquid. The pump body is constructed of impact and corrosion
resistant plastic. Tubing is held firmly in place by the pump body haves-no
clamps are required. The intake line is air purged before and after each
sample. The duration of the pre and post sample purge automatically
compensates for different intake line lengths. The pump tubing is 0.95 cm
(3/8 in.) ID X 0.32 cm (1/8 in.) wall medical grade silicone rubber. Although
the pump is capable of vertical lifts up to 8.2 m (27 ft), lifts greater than 6.7 m
(22 ft) are not recommended unless the Remote Pump option is utilized. The
pump produces a sample transport velocity of 1 mps (3.3 fps) at 1 m (3 ft)
vertical lift. The sample is under pumped flow at all times from the source
stream to the sample container, thereby keeping solids in suspension.
The interface connectors are located on the left side of the controller housing.
The sampler comes standard with two interface receptacles:
• 12 V dc (Power Input)
• Auxiliary (Multi-purpose input/output port)
Interface receptacles are covered with push-on receptacle caps. These caps
protect the connector pins from dirt and moisture and should be attached to
any receptacle not in use.
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General Information