The SR50A is a rugged acoustic sensor for measuring the distance from the sensor to a target. This sensor is typically used for snow depth or water depth measurements, but it is well-suited for other uses.
Because the speed of sound in air varies with temperature, an independent temperature measurement is required to compensate the distance reading. A simple calculation is applied to initial readings for this purpose.
Note: Campbell Scientific recommends model SR50A-316SS-L for marine environments.Read More
|Measurement Time||< 1.0 s|
|Measurement Range||0.5 to 10 m (1.6 to 32.8 ft)|
|Output Options||SDI-12 version 1.3, RS-232, RS-485 (output options selected by configuring internal jumpers)|
|Baud Rates||1200 to 38400 bps (RS-232, RS-485 modes)|
|Power Requirements||9 to 18 Vdc (typically powered by data logger’s 12 Vdc power supply)|
|Resolution||0.25 mm (0.01 in.)|
|Accuracy||±1 cm (0.4 in.) or 0.4% of distance to target (whichever is greatest). Requires external temperature compensation.|
|Operating Temperature Range||-45° to +50°C|
|Length||10.1 cm (4.0 in.)|
|Diameter||7.5 cm (3 in.)|
|Cable Weight||250 g (8.2 oz) for a 4.57-m (15-ft) cable|
Maximum Cable Length
|-NOTE-||Cable lengths greater than 60 m require a heavier gage wire if the power supply drops below 11 Vdc.|
|SDI-12||60 m (196.9 ft)|
30 m (98.4 ft)
Baud rates ≤ 9600 bps
|RS-485||300 m (984.3 ft)|
|Active||250 mA (typical)|
|Quiescent SDI-12 Mode||< 1.0 mA|
|Quiescent RS-232/RS-485 Modes||
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
One single-ended channel per probe is required; an excitation channel can be shared by several probes.
Number of FAQs related to SR50A: 17
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No. The maximum cable length is approximately 800 ft.
Approximately 800 feet. This is a function of the limitations of the SDI-12 signal.
Yes. This sensor has an SDI-12 output.
No. This causes echoes and reflections that confuse the sensor.
Yes. The accuracy of the sensor is 1 cm or 0.4% of distance to water (whichever is greater). As long as the water level is deeper than this, the water height can be confidently determined.
Yes, but more routine maintenance of the sensor is needed in marine environments.
This sensor requires regular maintenance in a marine environment. The SR50A-L functions properly if care is taken to keep the vent free of salt accumulation and the interior free of moisture by replacing the desiccant as needed. It may also be necessary to carefully clean the face of the sensor to remove salt deposits.
The potential error is roughly ±0.4% of distance for a ±25° Celsius variation away from 0° Celsius.