 
                
			
			
				| Services Available | |
|---|---|
| Repair | No | 
| Calibration | No | 
| Free Support | No | 
The OBS-3 measured both turbidity and suspended solids. Its turbidity range was 0 to 4000 NTU. A nearly linear response to particle concentrations of turbidity spanned more than three orders of magnitude. (OBS® is a registered trademark of Campbell Scientific.)
 
				Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
| Product | Compatible | Note | 
|---|---|---|
| 21X (retired) | ||
| CR10 (retired) | ||
| CR1000 (retired) | ||
| CR10X (retired) | ||
| CR200X (retired) | ||
| CR206X (retired) | ||
| CR211X (retired) | ||
| CR216X (retired) | ||
| CR23X (retired) | ||
| CR295X (retired) | ||
| CR3000 (retired) | ||
| CR500 (retired) | ||
| CR5000 (retired) | ||
| CR510 (retired) | ||
| CR800 (retired) | ||
| CR850 (retired) | ||
| CR9000 (retired) | ||
| CR9000X (retired) | 
| Non-Linearity of Turbidity | 2% (formazin, 0 to 2000 FTU) | 
| Drift | < 5% (per year) | 
| Settling Time | < 1 s | 
| Input Voltage | 9 to 16 Vdc | 
| Infrared Wavelength | 875 nm | 
| Maximum Depth | 500 m (1640.5 ft) | 
| Diameter | 3 cm (1.2 in.) | 
| Length | 18 cm (7.1 in.) | 
| Weight | 181.4 g (0.4 lb) |