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 the pressure sensor installed. (OBS® is a registered trademark of Campbell Scientific.)Read More
The heart of the OBS-3A monitoring system is an OBS® 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 are selected as an option (see Ordering Info).
The monitor uses HydroSci software running under Windows XP, 7, and 8.
|Maximum Depth||300 m (984 ft)|
|Operating Temperature Range||0° to 35°C|
|Storage Temperature Range||-20° to +70°C|
|Drift over Time||< 2% per year|
|Drift over Temperature||0.05% per °C|
|Maximum Sample Size||2048|
|Sampling Rate||1 to 25 Hz (when connected to a PC)|
|Maximum Data Rate||5 Hz|
|Data Capacity||8 MB|
|Maximum Number of Data Lines||200,000|
|PC Interfaces||RS-232/115 kbps, RS-485/115 kbps|
|Battery Capacity||18 Ahr|
|Maximum Battery Life||8,000 h|
|Infrared Wavelength||850 nm|
|Diameter||7.6 cm (3.0 in.)|
|Length||36.2 cm (14.3 in.)|
|Weight||1.5 kg (3.4 lb)|
|Pressure||0 to 10, 20, 50, 100, or 200 m|
|Turbidity||0.4 to 4,000 NTU|
|Temperature||0° to 35°C|
|Conductivity||0 to 65 mS/cm (40 PSU, o/oo)|
|Pressure||±0.5% of f.s. (where f.s. = 50, 100, or 200 dBar)|
Campbell Scientific offers a choice of field cables used to connect the OBS-3A to a PC for system configuration. The cables differ in their length. The ResourceDVD shipped with the OBS-3A includes the HydroSci support software.
HydroSci is used to configure and extract data from the CRS45X Recording Submersible Pressure Transducer and the OBS-3A Turbidity and Temperature Monitoring System.View Update History