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SR-1101 Fish Counter

Simultaneous Upstream and Downstream Counting

Automatically compensates for changes in water conditions and offers over 95% counting accuracy. Battery or AC powered operation.

The SR-1101 Fish Counter provides a state-of-the-art fish counting system. It is designed for counting operations requiring information about both upstream and downstream fish movements. The SR-1101 provides field reliability, simplicity of operation and ease of installation.

The SR-1101 uses a single counting tunnel with metal rings, flush-mounted, on the inner surface. The passage of fish through the counting tunnel causes water conductivity changes. Special logic in the SR-1101 allows it to discriminate between upstream and downstream fish passages. Two six-digit liquid crystal displays (LCD) tally completed fish passages. The displays are easy to read even in direct sunlight.

Special Features

The SR-1101 employs an Auto-Balance system which compensates for changes in water conductivity, water temperature and marine growth. The Auto-Balance feature makes it possible to set it and forget it for unattended counting operations.

A wide-range Sensitivity Control determines the minimum size of fish that will be counted. Maximum sensitivity depends on the ratio of tunnel to fish dimensions. For best counting accuracy, tunnel diameter to fish length should not be more than one-to-one.

Output signals are provided which may be used to drive remote tally units, digital cameras or other devices. The system easily tallies five counts per second, giving 18,000 counts per hour.

Water Conditions

The SR-1101 Fish Counter is designed to work in fresh water within a conductivity range of 20 to 500 microSiemens/cc. The submerged counting tunnel should be mounted in a location to produce a velocity through the tunnel sufficient to sweep through fishes desiring to rest within the tunnel, i.e., water velocity through the counting tunnel should be equal to, or greater than, the sustained swimming ability of the fish. With a correct tunnel-size to fish-size ratio, count accuracy is typically better than 95%.

Power Requirements

The SR-1101 Fish Counter can be powered from either 120 VAC 60 Hz or from the optional 1101-RB internal rechargeable battery. The battery life varies from five to seven days, depending on water conductivity and tunnel size. A low-battery indicator will provide a warning several days before a battery change is required. When powered from 120 VAC the battery is kept fully charged at all times. An internal stand-by battery is provided to preserve count data when the AC power is turned off or when the 1101-RB battery is being replaced.


The SR-1101 Fish Counter features a rugged all-welded aluminum case. The case has a top cover with a see-through window which allows observation of count data while providing protection from rain and wet environment.

Type of Detection Potentiometric bridge
Water Conductivity Range 20 to 500 ┬ÁS/cm
Count Sensitivity 1% tunnel unbalance, minimum
Count Rate 5 per second
Count Capacity per Channel 999,999 six digit LCD
Counting Mode Directional
Type of Tunnel Required Three element potentiometric
Tunnel Diameters 1 in. to 12 in. standard
Tunnel Length:Diameter 3:1 minimum
Auto Balance Range 5% tunnel unbalance
Smallest Fish Detected Length equal to tunnel diameter
Data Output Signals 0 to 12V pulse for each count
Power Requirement 120VAC 60Hz or 12VDC
Battery Life 5 days minimum
Size and Weight Height: 6.75 in.
Width: 13.5 in.
Depth: 6.25 in.
Weight: 4 lb. (17 lb. with battery)

Specifications subject to change without notice.