|Teledyne Isco 4150 Area Velocity Flow Logger
with Low Profile Sensor
January 1, 1998 – February 9, 2006
There shall be furnished an open channel flow logger suitable for multi-site monitoring. An area velocity sensor shall be used to measure flow rate.
A)The sensor shall directly measure average liquid velocity using the ultrasonic Doppler technique. The sensor shall not require a multiplying factor based on flow depth to convert a point velocity to the average liquid velocity. The sensor shall not require velocity profiling and calibration at the measurement site. The sensor shall not contain electrical contacts exposed to the liquid to measure velocity.
i)The Doppler velocity measurement frequency shall be 500 kHz with a transmission angle of 20 degrees. The velocity measurement range of the sensor shall be from -5 to +20 feet per second (-1.5 to +6.1 meters per second). The velocity in water with a uniform velocity profile and a speed of sound of 4850 feet per second (1480 meters per second) shall be measured with a maximum error of +/-0.1 feet per second (+/-0.03 meters per second) over a range of -5 to +5 feet per second (-1.5 to +1.5 meters per second), and +/-2% of reading over a range of 5 to 20 feet per second (1.5 to 6.1 meters per second). The typical minimum depth for velocity measurement shall be 0.08 feet (0.025 m).
B)The sensor shall also contain a differential integrated circuit pressure transducer to measure the hydrostatic pressure of the liquid to determine the liquid depth.
i)The level measurement range of the sensor shall be from 0.033 to 10.0 feet (0.010 to 3.05 m). The level shall be measured with a maximum error of +/- 0.008 feet per foot (+/- 0.008 m per m) over a range of 0.033 to 5.0 feet (0.010 to 1.52 m), and +/- 0.012 feet per foot (+/- 0.012 m per m) for levels greater than 5.0 feet (1.52 m). The temperature coefficient shall be +/- 0.0023 feet per degree F (+/- 0.0013 m per degree C) over the compensated temperature range of 32 to 122 degrees F (0 to 50 degrees C).
C)The sensor shall be 0.75 inches (1.9 cm) in height and 1.31 inches (3.3 cm) in width. The sensor cable shall be 25 feet (7.62 m) long. The cable shall terminate in a sealed, military style connector so that the sensor can be easily replaced in the field. The connect cable for the sensor shall include a vent tube that shall reference one side of the pressure transducer to atmospheric pressure. [An optional (25 ft. - 7.62 m) vented extension cable shall be supplied.]1 Sensor materials exposed to the flow stream shall be epoxy, stainless steel, polyvinyl chloride (PVC), and chlorinated polyvinyl chloride (CPVC).
A)Measured liquid level readings shall be converted into the area of the flow using internal conversion algorithms. The flow logger shall contain conversion information for round, U-shaped, rectangular and trapezoidal channels. The flow logger shall also accept up to 50 level-area points.
i)Alternatively, measured liquid level readings shall be converted into corresponding flow rate readings using internal conversion algorithms. The flow logger shall accept conversion information for V-notch weirs, rectangular weirs with and without end contractions, Cipolletti weirs, and Parshall, Palmer-Bowlus, Leopold-Lagco, trapezoidal, and H flumes. For monitoring in applications using the Manning formula in round, U-shaped, rectangular, and trapezoidal channels, the flow logger shall accept information for channel configuration and size, and slope and roughness coefficient. The flow logger shall accept up to 50 level-flow rate points. The flow logger shall accept a two-term, level-flow rate polynomial equation.
B)Optionally, the flow logger shall be connected to a tipping bucket rain gauge which tips every 0.01 inch (0.25 mm) or 0.004 inch (0.1 mm) of rainfall.2
C)The flow logger shall be capable of activating a connected sampler based on any combination of any four AND/OR operators derived from the parameters of level, velocity, flow rate, and rainfall.
i)The flow logger shall have a 12 volt pulse output for signaling a connected automatic sampler to collect flow-paced samples. The flow logger shall have inputs to accept signals from the sampler indicating when a sample is collected and the bottle in which the sample is placed.
D)The internal data storage memory in the flow logger shall have a capacity of 230,000 bytes, divided into up to 6 user-defined partitions. Each partition shall be programmable to store level, velocity, flow rate, rainfall, or sample data. Timing for the data storage shall be selectable in 1, 2, 5, 10, 15, 30, 60, or 120 minute intervals. Each partition shall be programmable to operate in either rollover, slate or triggered slate mode. Triggering events in slate mode shall be selectable from level, velocity, flow rate, rainfall, and time.
E)The flow logger shall be programmed using a software program that shall operate on an IBM PC or compatible computer. The software shall also retrieve stored data from the flow logger, and generate graphs and reports from stored data. The computer shall communicate with the flow logger using a direct RS-232 connection or a 2400 baud telephone modem in the flow logger.3
i)The flow logger shall be programmed to dial out based on any combination of any four AND/OR operators derived from the parameters of velocity, level, flow rate, and rainfall. The flow logger shall call up to 5 telephone numbers with a programmable delay between each call. The telephone modem shall have voice messaging capability. Acknowledgment of the alarm shall be via touch tones or a call back to the flow logger.
F)The program memory in the flow logger shall be non-volatile, programmable flash memory. The program memory shall be capable of being updated via the serial port on the flow logger without opening the enclosure.
G)The flow logger shall require 12 volt DC power for operation. Power shall be supplied from [(two internal 6 volt alkaline lantern batteries)(an internal rechargeable lead acid battery)(an external rechargeable lead acid battery with solar panel battery charger)(companion Isco sampler)(external user-supplied 12 volt DC source)(external 120 or 240 volt AC power pack).4 Typical battery life with two internal 6 volt alkaline lantern batteries and 1 hour reading intervals shall be 1 year.
H)The flow logger shall be housed in a rugged, submersible, watertight, dust-tight, corrosion-resistant (self-certified NEMA 4X, 6 and IP67) enclosure. An internal, easily replaceable, rechargeable desiccant canister shall keep the battery compartment of the flow logger free of moisture. An internal bag of rechargeable desiccant shall keep the electronics compartment of the flow logger free of moisture. A humidity indicator shall indicate, through a window in the enclosure, the humidity level inside the electronics compartment.
1 Specify optional vented extension cable.
2 Specify optional tipping bucket rain gauge.
3 Specify optional 2400 baud telephone modem with voice messaging.
4 Specify one or more power sources as desired.
Teledyne Isco 4150 Area Velocity Flow Logger with Low Profile Sensor
Engineering Specifications / Page of