Monitoring Storm Water - Water and Wastewater - Stormwater

 (environmental-expert.com)https://www.environmental-expert.com/companies/optical-scientific-inc-osi-1352/products/family-weather-sensors-8583

The APG-815 is a unique and very advanced sensor for measurement and discrimination of various types of precipitation, unmatched by any other technology in terms of accuracy,
performance, ultra-low maintenance and high reliability.

The following are specifications and features that together are unique to the APG:

• Measurement principle: Optical Scintillation (far more reliable than optical scatter and
  mechanical techniques)
• Algorithms continually refined from over 800 million hours of proven field operation in
  applications on every continent
• Discriminates between rain, snow, drizzle, freezing drizzle, freezing rain, etc.
• Ability to add acoustic hail / ice particle sensor (HIP-100)
• Minimum 10 weather identification codes for both NWS and WMO weather codes
• Measurement dynamic range: 0.001 to 500 mm/hr rain, .03 to 500 mm/hr snow
• Optional extended measurement ranges over 500 mm/hr
• Reports both instantaneous rain rate and accumulation
• Rain / snow measurement accuracy: 5% accumulation
• Rain / Snow measurement resolution: 0.001 mm

Features & Benefits

• All digital / DSP based design with no temperature sensitive analog components
• No Moving Parts
• No small collection or measurement orifices to get clogged with dirt / debris
• No need for high power heaters or chemical antifreeze for snow measurement
• No periodic maintenance required
• No scheduled / regular cleaning of optics required
• Insensitive to dirt buildup on optics
• Built-in continuous self-test / self-diagnostics and performance monitoring
• Ultra-reliable operation 24/7/365 with virtually zero maintenance
• Mean-Time Between Failure (MTBF) in excess of 80,000 hours
• No adverse effects from high winds, evaporation and other common errors of
  mechanical gauges
• Technology field proven for over 30 years (long track record)
• Can operate on unstable / tilting platforms such as data buoys and ships
• Easy installation / no cement pads; simply clamp to a 1.5-2” pipe w provided U-bolts

Communications: 

• Simple polled / unpolled (user selectable) ASCII data string over RS-232
• Include MODBUS RTU over serial RS-232 I/O format as standard
• Options for RS-485, Ethernet, Limited Distance Modems (LDM) & Cellular Modems
  
• Full data update rate; once per minute; Instantaneous intensity every 10 seconds
• Power requirements: nominal 12 VDC / max 400 mA (solar compatible)
• Operating temperature range; -50° to 60° C (-58° to 140° F)
  

Widely used by NOAA / NWS, military, airports, state DOTs, etc.