Stevens A Series - Introduction; General Description; Safety Information

1 Introduction
1
1.1 General Description
The Stevens Type A is a float-operated
recorder that provides a permanent,
continuous, long-term graphic record of
water level fluctuations. A precision clock
movement controls the rate at which the
strip chart is advanced. The rise and fall in
of the float moves a marking stylus laterally
across the chart. The stylus or pen will
reverse at each margin so that any range
of water level stage change can be
accommodated.
The water level recording ratio, called
"gage scale", is also selectable. One
traverse across the chart width can
represent anywhere from .25 meters to
12.5 meters of water level change for
Metric models, and 1 foot to 50 feet for
English models (reference Table 5 & 6).
Chart drive is normally accomplished by
use of a battery-operated Quartz
Multispeed Timer unit, using an electronic
control circuit. A wide range of chart
speeds, called "time scales", may be
selected (reference Table 1).
1.2 Safety Information
Before performing any procedure in this
manual, read all applicable warnings and
cautions.