SR50ATH Sonic Distance Sensor with Heater and Temperature Sensor

Overview

The SR50ATH is a sonic distance sensor with an integrated external temperature probe and heater. Sonic sensors determine distance by emitting an ultrasonic pulse and then measuring the elapsed time between the emission and return of the pulse. The temperature probe allows the SR50AT series to output temperature-corrected values (speed of sound varies with temperature). The integrated heater prevents ice and rime from coating the transducer.

Note: Campbell Scientific recommends model SR50AT-316SS-L for marine environments.

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Benefits and Features

  • Integrated temperature probe for providing temperature correction of measurements
  • Non-contact method for determining snow depth
  • Wide operating temperature range
  • Integrated transducer heater; rugged enough for rime and ice environments
  • User-selectable options for output
  • Uses a multiple echo processing algorithm to help ensure measurement reliability
  • Compatible with most Campbell Scientific data loggers

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Detailed Description

The SR50ATH is an identical unit to the SR50A with the addition of an external temperature sensor and transducer heater. The temperature sensor requires a six-plate radiation shield. The addition of a heating element around the transducer prevents ice and rime from coating the transducer with minimal power requirements. The SR50ATH outputs a temperature-corrected distance reading, eliminating the need for further post-processing, as well as a separate temperature reading.

The SR50ATH was designed to meet the stringent requirements of measuring snow depths and uses a multiple echo processing algorithm to help ensure measurement reliability. The SR50ATH is compatible with all current Campbell Scientific data loggers, as well as many other data acquisition systems.

Specifications

Measurement Time < 1.0 s
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)
Quiescent Power Consumption in SDI-12 Mode < 1.0 mA without heater
Quiescent Power Consumption in RS-232/RS-485 Mode
  • < 1.25 mA (≤ 9600 bps) without heater
  • < 2.0 mA (> 9600 bps) without heater
Active Power Consumption 250 mA typical without heater
Measurement Range 0.5 to 10 m (1.6 to 32.8 ft)
Beam Acceptance ~30°
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
Temperature Accuracy
  • ±0.2°C (at 0° to 50°C)
  • ±0.75°C (at -45° to 0°C)
Compliance CE compliant
Diameter 7.5 cm (3 in.)
Length 10.1 cm (4.0 in.)
Weight 375 g (13.2 oz) without cable
Cable Weight 250 g (8.2 oz) for a 4.57-m (15-ft) cable

Heater

Heater Resistance 75 ohm
Nominal Operating Voltage 12 V (ac or dc) Use a properly conditioned low-noise power source. A noisy power source will affect operation of the sensor.
Maximum Rated Wattage 3 W
Maximum Rated Voltage 15 V (ac or dc)
Maximum Operating Temperature 25°C (Turn the heater power off at temperatures above 25°C. This prevents damage to the sensor and reduces power consumption.)

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 (200 ft)
RS-232 60 m (200 ft) Baud rates ≤ 9600 bps
RS-485 300 m (984 ft)

Compatibility

Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.

Data Loggers

Compatible Note
21X (retired) SDI-12
CR10 (retired) SDI-12
CR1000 (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR1000X SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR10X (retired) SDI-12
CR200X (retired) SDI-12
CR206X (retired) SDI-12
CR23X (retired) SDI-12
CR295X (retired) SDI-12
CR300 SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR3000 (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR310 SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR350 SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR500 (retired) SDI-12
CR5000 (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR510 (retired) SDI-12
CR6 SDI-12, RS-232, and RS-485
CR800 (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR850 (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.
CR9000 (retired)
CR9000X (retired) SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.

Distributed Data Acquisition

Compatible Note
GRANITE 6 SDI-12 and RS-232. For RS-485, requires an MD485 interface or similar RS-485 to RS-232 interface.

Additional Compatibility Information

Data Logger Considerations

One single-ended channel per probe is required; an excitation channel can be shared by several probes.


Downloads

SR50ATH heater control programs v.1 (5 kB) 22-01-2020

CR6 and CR1000X programs that read the SR50ATH SDI-12 output and control the SR50ATH heater. The programs use the data filtering method described in the manual.

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