OBS-3A

Turbidity and Temperature Monitoring System

The OBS-3A combines our OBS® probe with pressure, temperature, and conductivity sensors in a battery-powered recording instrument. Batteries and electronics are contained in a housing capable of operating at depths of up to 300 meters, depending on which pressure sensor is installed.

The heart of the OBS-3A monitoring system is an optical backscatter sensor for measuring turbidity and suspended solids concentrations. This sensor detects near infrared (NIR) radiation scattered from suspended particles.

A fast-response, stainless-steel-clad thermistor monitors temperature. Pressure is measured with a semiconductor piezoresistive strain gage, and conductivity is measured with a four-electrode conduction-type cell. Working depths of the pressure sensor is selected as an option.

The monitor is operated with software running under Windows 98, 2000, and XP.

Features

No cable required, runs 1500–8000 hours on 3 D-cell batteries
Measures sediment concentrations to 5000 mg/l and turbidity to 4000 NTU with field-proven OBS technology (U.S. Patent No. 4,841,157)
Logs depth, wave height, wave period, temperature, and salinity
Records 200,000 lines of data in flash memory
Program setpoints and sampling times