SR-1601 Fish Counter

The SR-1601 Fish Counter is a 16-channel counter designed for counting hatchery fry, migrating smolt, fish eggs, emergent shrimp, and other macro organisms. The SR-1601 simultaneously monitors all sixteen tunnels for fish movements, giving individual counts for each tunnel. In order to be counted, macro organisms pass through a counting tunnel and are tallied on a 16-digit display. The system easily tallies ten counts per second per channel, giving 576,000 counts per hour.

The SR-1601 uses multiple counting tunnels that are separate potentiometric bridges. The passage of fish or eggs through each tunnel causes corresponding water conductivity changes. With a proper tunnel-size to fish-size ratio, count accuracy is typically better than 98%. For best counting accuracy, tunnel diameters should not be more than one-half the length of the fish to be counted. These are counted by the SR-1601 and displayed on separate LCDs. Any number of tunnels from one to sixteen may be used at one time.

Water Conditions

The SR-1601 is designed to work in fresh water within a conductivity range of 20 to 500 microSiemens/cc. The submerged counting tunnels are arranged to produce a velocity through the tunnels sufficient to overcome the fishes' swimming ability. The fish in the vicinity of the tunnel entrances are pulled through by the water flow. Water velocity should be equal to the burst swimming speed of the fish.

Power Requirements

The SR-1601 can be powered from either 120 VAC 60 Hz, or from the optional internal rechargeable batteries. If the batteries are installed, the counter will continue to operate for up to four days when AC power is lost. If extended operation from battery power is necessary, an external battery connector is provided. A low-battery indicator is provided to give several hours advanced warning before a battery change is required. When the SR-1601 is powered from 120 VAC, the battery is kept fully charged at all times. A secondary internal stand-by battery is provided to preserve count data on all channels when the AC power is turned off or when the internal battery is being replaced.


The SR-1601 Fish Counter features a rugged all-welded painted aluminum case. The case is weather resistant and has a top cover with a see-through window which allows observation of count data while maintaining water resistance.

SR-1601 Fish Counter Specifications

Type of Detection Potentiometric bridge
Water Conductivity Range 20 to 500 ┬ÁS/cm
Count Sensitivity 1% tunnel unbalance, minimum
Count Rate 10 per second/channel
Count Capacity per Channel 999,999 six digit LCD
Counting Mode 16 discrete channels
Type of Tunnel Required Three element potentiometric
Tunnel Diameters 1 in. to 3 in. standard
Tunnel Length:Diameter 3:1 minimum
Smallest Fish Detected Length equal to tunnel diameter
Power Requirement 120VAC 60Hz
Battery Life 4 days minimum
Size and Weight Height: 9.2 in.
Width: 21.5 in.
Depth: 9.5 in.
Weight: 16.5 lb. (35 lb. with battery)

Specifications subject to change without notice.