簡介
·標準和低斷面面積流速傳感器
·美國ISCO 4250速度面積便攜式流速聲波測量儀探頭的流線型造型避免了物殘渣和水流中化學成分的腐蝕
·密封設計能避免油脂堵塞，從而使其長期運行
·標準探頭適用于較大管徑，帶有高濃度懸浮固體和氣泡的混濁水流
·低斷面探頭適用于淺流，水位可1英寸（25毫米） ·可選擇電話調制器-提供獲取遠程數據，語音信息，和警報信號
·可以支持不過3個單獨的內部4-20mA輸出
·美國ISCO 4250速度面積便攜式流速聲波測量儀即便在槽或堰不適用、探頭被浸沒、滿管、過載或有逆流發生的地方
·4250均可為您提供較高的測量，現場顯示和打印

特點
·打印顯示一體式結構
·帶有微處理器的數字探頭讀數穩定（液位偏差）
·無需量程校準現場一點校準
·沒有溫度漂移
·自動修正泥沙液位
·對各種不同的液體自動增益控制
·傳感器不受液位降低影響

應用場合
·容量評價
·入流和滲流研究
·下水道溢流研究
·生活污水評估
·明渠流量測量

技術參數
液位測量方法 浸入式壓力傳感
液位測量范圍 0.015至3.05m，可延伸至0.015-9.14m
液位準確性 &plun;0.008/m
速度測量方法 多普勒聲波方法
頻率 500KHz
速度范圍 -1.5至6.1m/s
速度準確性 -1.5至1.5m/s，&plun;0.03m/s，1.5至6.1m/s, &plun;2%
模塊存儲溫度 -40~60℃
操作溫度 -18&plun;～60℃
電源 12～14V DC
護等級 IP65
數據存儲間隔 1分鐘到120分鐘可選擇
模塊尺寸 40.6＊29.2＊26.7cm
溫度影響 &plun;0.0027m/℃
標準傳感器尺寸 16.8＊4.1＊3.0cm
標準傳感器重量 0.96kg
電纜線長 7.6m， 可延長至15.2m

The sensor on the Isco 4250 uses patented Doppler technology to direly measure average velocity in the flow stream. An integral pressure transducer measures liquid depth to determine flow area. The 4250 then calculates flow rate by multiplying the area of the flow stream by its average velocity.

The 4250 gives you greater accuracy in applications where weirs or flumes are not praical, or where submerged, full pipe, surcharged and reverse flow conditions may occur. With area velocity you don’t have to estimate the slope and roughness of the channel. And Isco’s exclusive 500 kHz Doppler penetrates farther into deep flow streams than 1 MHz systems, whose shorter wavelength can cause them to give “nearsighted” velocity measurement in tical wastewater applications. The Doppler system continuously profiles the flow stream, eliminating profiling and calibration required by eleromagnetic systems.

Standard Features


4200 Series
- Built-in flow conversions for most applications, including Manning formula, data points, or equation for special situations.
- Set up with or without a computer. All setup funions can be done either via onboard kead and two-line x 80-charaer backlit LCD, or by conneion to PC with Flowlink software.
- Built-in dot matrix printer gives you an accurate, on-site printout
- Internal memory stores over 2 months of flow, rainfall, parameter, and sample data at 15 minute intervals.
- Outputs for Sampler aivation, alarm outputs
- Inputs for conneion to 674 Rain Gauge and multiparameter water quality sonde,

4250 Area Velocity
- Sealed Area-Velocity sensor resists fouling by oil and grease. Streamlined shape sheds debris.
- Choice of standard (10 ft) and extended (30 ft) level measurement range.
Applications


Accurate open channel flow measurement without a weir or flume

Pretreatment Compliance

Stormwater Runoff Monitoring

Permit Enforcement

er Flow Monitoring

Combined er Overflow Studies

Inflow and Infiltration Studies

River and Stream Gauging
Options and Accessories


Choice of Standard and Low Profile Area Velocity Sensors.
- Standard Sensor is recommended for larger pipes and turbid flows with high concentrations of suspended solids and entrained air.
- Low Profile Sensor is recommended for shallows flows, tically down to 1" (25 mm).

Optional telephone modem - provides remote data retrieval, voice messaging, and dial-out alarm conditions

Analog Outputs - up to 3 isolated internal 4-20 mA outputs

Mounting rings for installation of probe in round pipes from 6 to 15 inches in diameter

Non-resettable totalizer

674 Rain Gauge

581 RTD data retrieval device downloads up to 20 meters

201 pH module adds pH and temperature measurement/logging

YSI 600 Multi-Parameter Water Quality Monitor

Suspension equipment (to hang flowmeter in manhole)
Specifications
Size (H x W x D): 17.0 x 11.5 x 10.5 in. (43 x 29 x 26.7 cm) (without power source)
Weight: 17.3 lbs (7.8 kg) (without power source)
Material: High-impa molded polystyrene struural foam
Enclosure: NEMA 4X (iP65)
Power: 12 to 14V DC, 14 mA average at 12.5V DC
Tical Battery Life (printer set at 1 in/hr, 1 minute level reading interval, 5 minute velocity reading interval)
934 Nickel-Cadmium Battery: 8 to 11 days
946 Lead-Acid Battery: 12 to 16 days
948 Lead-Acid Battery: 2½ to 3 months
Program Memory: Non-volatile, programmable flash. Updateable without opening enclosure.
Display: Backlit LCD, 2-line, 80-charaer (5.5 mm high x 3.2 mm wide)
Level-to-Area Conversions
Channel shapes: Round, U-shaped, reangular, trapezoidal
Data points: Four sets of 50 level-area points
Level-to-Flow Rate Conversions
Weirs: V-notch, reangular, Cipolletti
Flumes: Parshall, Palmer-Bowlus, Leopold-Lagco,Trapezoidal, H, HS, HL
Manning Formula: Round, U-channel, reangular, trapezoidal
Data Points: Four sets of 50 level-flow rate points
Equation: Two-term polynomial
Totalizers
LCD: Total, forward, and reverse flow; 9 dis each, floating decimal point, resettable
Mechanical (optional): Total flow, 7 dis, non-resettable
Area Velocity Sensor (See separate specifications for low-profile sensor)
Size (LxWxH): 6.6 x 1.6 x 1.2 inches (16.8 x 4.1 x 3.0 cm)
Weight, incl. cable: 2.1 lbs (0.96 kg) for standard probe with 25 foot cable; 3.9 lbs (1.8 kg) for extended range probe with 50 ft cable.
Ambient Operating Temperature Range: 0° to 140°F (-18° to 60°C)
Compensated Temperature Range: 32° to 140°F (0° to 60°C)
Materials: Polybutadiene-based polyurethane, stainless steel; PVC and CPVC cable
Velocity Measurement
Method: Doppler Ultrasonic, 500 kHz
Velocity range: -5 to +20 ft/s (-1.5 to 6.1 m/s)
Level Measurement
Method: Submerged pressure transducer
Standard range probe: measurement range 0.05 to 10 ft (0.015 to 3.05 m); max level 20 ft (6.1 m)
Extended range probe: measurement range 0.05 to 30 ft (0.015 to 9.14 m); max level 40 ft (12.2 m)
Standard probe accuracy (Non-linearity, repeatability, and hysteresis at 25°C (77°F). Max error for indicated level range.
0.033 to 5.0 ft (0.01 to 1.52 m): &plun;0.008 ft/ft (&plun;0.008 m/m)
>5.0 ft (>1.52 m): &plun;0.012 ft/ft (&plun;0.012 m/m)
Extended probe accuracy (Non-linearity, repeatability, and hysteresis at 25°C (77°F). Max error for indicated level range.
0.05 to 15 ft (0.015 to 4.57 m): &plun;0.03 ft (&plun;0.009 m)
0.05 to 21 ft (0.015 to 6.4 m): &plun;0.09 ft (&plun;0.027 m)
0.05 to 30 ft (0.015 to 9.14 m): &plun;0.3 ft (&plun;0.09