Hach 911, User Manual

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5
Specifications
Submerged Area/Velocity Sensor
Velocity Measurement
Method: Doppler Ultrasound Twin 1 MHz piezoelectric crystals
Typical Minimum Depth: 2 cm (0.8 in.)
Zero Stability: 0.015 m/s (<0.05 ft/s)
Accuracy: ± 2% of reading
1
Recommended Range: –1.52 to 6.10 m/s (–5 to 20 ft/s)
Depth Measurement
Method: Pressure transducer with stainless steel diaphragm
Accuracy (static)
2
:
±0.16% full scale ±1.5% of reading at constant temp (± 2.5 °C)
±0.20% full scale ±1.75% of reading from 0 to 30 °C (32 to 86 °F)
±0.25% full scale ±2.1% of reading from 0 to 70 °C (32 to 158 °F)
Velocity-Induced Depth Error: Compensated based on pipe geometry and flow velocity.
Depth Range:
Standard: 0–3 m (0–10 ft); Extended: 0–9 m (0–30 ft)
Air Intake Atmospheric pressure reference is desiccant protected.
Operating Temperature 0 to 70 °C (32 to 158 °F)
Depth Compensated
Temperature
0 to 70 °C (32 to 158 °F)
Material Noryl
®
plastic outer shell with epoxy potting within
Power Consumption

1.2 W @ 12 VDC
Cable Material Urethane sensor cable with air vent
Cable Lengths Available
Standard: 9, 15, 23, and 30.5 m (30, 50, 75, and 100 ft)
Custom: 30.75-76 m (101-250 ft) maximum
Cable Diameter 0.91 cm (0.36 in.)
Dimensions 2.3 cm H x 3.8 cm W x 13.5 cm L (0.9 in. H x 1.5 in. W x 5.31 in. L)
In-Pipe Ultrasonic Sensor
Operating Frequency 75 kHz
Accuracy
±0.027 ft for sensor to liquid distance between 2.5 inches and 5 ft at ±1 ft change in head from
calibration point, 20 °C still air, ideal target, 25 ft cable.
Range
Distance from sensor to liquid: 0.2 inches (minimum) to 5 feet (maximum), @ 20 °C still air,
ideal target, 25 ft cable.
Resolution 0.019 cm (0.0075 in.)
Operating Temperature
Range
–20 to 60 °C (–4 to 140 °F)
Storage Temperature –20 to 60 °C (–4 to 140 °F)
Temperature Error 0.00005 meter/°C typical
Material Stat-Kon A-E ABS Plastic
Cable Length 7.6 m (25 ft) standard
Dimensions 4.44 cm (1.75 in.) maximum diameter, 31.435 cm (12.375 in.) long
Mounting
Dedicated Mounting Rings, Permanent Mounting Bracket (installs directly to pipe wall),
Adjustable Mounting Band Kit.
Downlook Ultrasonic Sensor
Table 2 940 Flow Meter Specifications (continued)