The Stingray open channel flow logger from Greyline Instruments Inc. enables technicians to monitor wastewater velocity and flow without entering manholes.
“A sewer manhole is a difficult environment. You don’t want to work an instrument keypad in one, if at all possible,” says Ernie Higginson, Greyline advertising manager. Compact and portable, the Stingray unit is designed for use in open channels, partially filled sewer pipes, and surcharged pipes. It works with municipal stormwater, combined effluent, raw sewage or irrigation water.
To deploy the unit, a technician affixes a stainless steel bracket 12 to 16 inches into the influent pipe (or to the bottom of an open channel), then slides a sealed, corrosion-resistant ultrasonic sensor into it. A cable connects the sensor to a watertight electronic logging unit that collects the sensor data.
The installer then sets the 3-pound logger to take readings at intervals from 10 seconds to 30 minutes, and hangs it inside the pipe. The logger records the date and time of the readings and the water level, velocity and temperature. PC software allows users to view the data in real time by connecting a laptop on site. The logger can store up to 130,000 data points.
After installation, the technician can press a button to activate an LCD display, which confirms that the unit is operating, and confirms the reading levels, signal and battery strength, and logger capacity. “You can leave the unit inside the pipe for up to three years, although a month is more typical,” Higginson says.
The calibration occurs after a technician downloads the log file into a computer, using an RS232 connection. After setting up parameters, such as the pipe diameter and the preferred unit of flow measurement (gpm, for instance), Windows-based software converts the collected data into a flow survey, including minimum, maximum and average flow. It can calculate flow for round, rectangular, trapezoidal and egg-shaped channels, and converts between common measurement units.
“You can bring a laptop computer on site and download the data, or bring the logger to a computer,” Higginson says. “After the data is downloaded, the software automatically creates a flow chart based on the pipe or channel size. The software displays it as a graph or a table, or you can export it to a spreadsheet program.”
The unit runs on four standard alkaline D flashlight batteries, and the software program is included. For information: 888/473-9546 or www.greyline.com.
