| Abstract: | A modified siphon sampler (or ‘single-stage sampler‘) was developed to sample shallow water at closely spaced vertical intervals. The modified design uses horizontal rather than vertical sample bottles. Previous siphon samplers are limited to water about 20 centimeters (cm) or more in depth; the modified design can sample water 10 cm deep. Several mounting options were used to deploy the modified siphon sampler in shallow bedrock streams of Middle Tennessee, while minimizing alteration of the stream bed.
Sampling characteristics and limitations of the modified design are similar to those of the original design. Testing showed that the modified sampler collects unbiased samples of suspended silt and clay. Similarity of the intake to the original siphon sampler suggests that the modified sampler would probably take downward-biased samples of suspended sand. Like other siphon samplers, it does not sample isokinetically, and the efficiency of sand sampling can be expected to change with flow velocity. The sampler needs to be located in the main flow of the stream, and is subject to damage from rapid flow and floating debris.
Water traps were added to the air vents to detect the flow of water through the sampler, which can cause a strong upward bias in sampled suspended-sediment concentration. Water did flow through the sampler, in some cases even when the top of the air vent remained above water. Air vents need to be extended well above maximum water level to prevent flow through the sampler. |
| Genre: | USGS Numbered Series |
| ProdID: | 80907 |
| Citation Author: | Diehl, Timothy H. |
| Citation Contributing Office: | Tennessee Water Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | |
| Citation Issue: | |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | iv, 13 p. |
| Citation Projection: | |
| Citation Public Comments: | Prepared in cooperation with the Tennessee Department of Transportation |
| Citation Publisher: | U.S. Geological Survey |
| Citation Series: | Scientific Investigations Report |
| Citation Series Code: | SIR |
| Citation Series Number: | 2007-5282 |
| Citation Search Results Text: | A modified siphon sampler for shallow water; 2008; SIR; 2007-5282; Diehl, Timothy H. |
| Citation Start Page: | |
| Citation Volume: | |
| Citation Year: | 2008 |
| Type: | citation/reference |
| Text: | A modified siphon sampler for shallow water; 2008; SIR; 2007-5282; Diehl, Timothy H. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/sir_2007_5282.jpg |
| URL (INDEX PAGE): | http://pubs.usgs.gov/sir/2007/5282/ |
| Date Other: | Sat, 26 Jan 2008 00:00 -0600 |
| Publisher: | U.S. Geological Survey |
