SDMS40 Multipoint Scanning Snowfall Sensor
Detects Onset of Snowfall and Snowmelt
Proven performance and field tested
weather applications supported water applications supported energy applications supported gas flux and turbulence applications supported infrastructure applications supported soil applications supported


The SDMS40 is a powerful and cost-effective 2D multipoint, laser-based snowfall sensor. In the past, multipoint laser-based snow depth sensors have typically been complex and costly, so the practical SDMS40 was developed to address those issues. Performance and reliability of the device have been proven with thorough testing of the sensor and its measurement method. (Read the white paper.) With the SDMS40, you can enjoy accurate data from a compact, automated, multipoint scanning laser snow depth sensor at a reasonable price.

The ability to quickly and reliably detect the onset of snowfall and snowmelt is a highly sought-after feature in a snow depth sensor, and the SDMS40 does not disappoint. It is one of a few laser sensor models available in the world that can reliably detect the onset of snowfall and snowmelt, and of all the models available, the SDMS40 is the most cost-effective.

Campbell Scientific prides itself on the high quality and accuracy of its products. We won't put our stamp of approval on anything that does not meet our expectations or the needs of our customers, and we want to ensure you can trust the quality and accuracy of the SDMS40 like you would trust any Campbell system. So we field tested the SDMS line of snow sensors over three Canadian winter seasons. It has proven itself to be practical, accurate, and of excellent quality.

Benefits and Features

  • Detects the onset of snowfall or snowmelt quickly and reliably
  • Proven performance by field tests over three winter seasons from 2013 to 2015
  • Allows easy installation on poles, building walls, or any structure
  • Can be used as an additional gauge to existing weather stations
  • Compact and light gauge structure
  • Less sensitive to ground conditions
  • Filters out noise input caused by obstacles and abnormal situations
  • Can operate on natural ground and different types of snow plates
  • SDI-12 and RS-232 output



Target Area Diameter 30 to 200 cm (11.8 to 78.7 in.) depending on installation height
Half Angle
Snow Depth Measurement Method Multipoint laser scanning
Number of Scanning Points 36
Measurement Range < 10 m (< 32.8 ft)
Mounting Height 1 to 5 m (3.3 to 16.4 ft) above maximum expected snowfall depth; maximum distance to targets is < 10 m (< 32.8 ft)
Gauge Pointing Angle 0 to 45°
Accuracy ±3 mm
Resolution 1 mm
Operating Temperature Range -40 to +50°C
Power Supply Requirements 12 to 15 Vdc, 2 A
Enclosure Classification IP67
Laser Classification 2
RoHS Compliant
Dimensions 12 x 28 x 10 cm (4.72 x 11.02 x 3.94 in.)
Weight ~1.8 kg (~3.97 lb)

Current Draw

Standby 50 mA
Active 250 mA
Heater 1300 mA


Communication Interfaces RS-232, RS-485, SDI-12
Maximum Baud Rate 57.6 (RS-232 and RS-485)
Default Baud Rate 9600


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

Data Loggers

Compatible Note
CR1000 (retired)
CR3000 (retired)
CR800 (retired)
CR850 (retired)


SDMS40 Example Programs v.1 (4 KB) 13-08-2020

Three example CR1000X programs. Two programs use SDI-12 and one program uses RS-232. All example programs read the sensor parameters and perform daily diagnostics. One SDI-12 program includes a constant table to allow the user to change the height and initial snow depth as needed for manual calibration. These programs require SDMS40 firmware v 7.4e or higher.

SDMS40 Firmware Update v.7.4e (864 KB) 26-06-2020

Latest firmware and utilities for the SDMS40.

View Revision History

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