Siemens 7ML19985AB01 instruction manual = head, cm = flow velocity, cm/sec

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TRAPEZOIDAL AREA X VELOCITY, P3 = 14

‘U’ parameters required *			‘U’ parameters calculated **
U0	= channel top width	B	U3 = area (h)
U1	= channel base width	b
U2	= channel depth	ht

*obtain from manufacturer’s specifications.

**calculated by OCM-3. May be viewed by accessing ‘U’ parameter.

Reference

ABSOLUTE CALCULATION, P4 = 0¤

For flows that can be calculated by the equation:

q = 1/1000 x (b + mh) x v

m = (B - b)/d

where : q = flow rate, l/sec

B = channel top width, cm

b = channel bottom width, cm d = depth of channel, cm

h = head, cm

v = flow velocity, cm/sec

RATIOMETRIC CALCULATION, P4 = 1¤

For flows that can be calculated by the equation:

q = qcal x A/Acal x v/vcal

A = (b + mh) x h

Acal = (b + mhcal) x hcal

m = (B - b)/d

where : q = flow rate, l/sec

B = channel top width, cm

b = channel bottom width, cm d = depth of channel, cm

h = head, cm

v = flow velocity, cm/sec

¤Refer to Operation \ Flow Calculation.

7ML19985AB01

OCM III

84

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Contents Open channel Contact Smpi Technical Publications at the following address Unit Repair and Excluded LiabilityTable of Contents Operation Start UPGeneral Keypad Initial Start Up Fundamental Checks Appendices Maintenance Error Codes 100 Communications 101 7ML19985AB01OCM If you want to know about Read Product About thisShort OCM IP65 enclosure Specifications» range 20 or 4-20 mA » resolution » 20 to 50 C -5 to 122 F» CE *, FM, CSA NRTL/C ProgrammerCabling Temperature SensorTransducer Output » Belden Communication SoftwareAuxiliary Input Outline and Mounting InstallationInstalling the OCM-3 OCM-3 Layout Customer device System DiagramOCM-3 Ground shield at OCM-3 only Installing the TransducerInstalling the Temperature Sensor Ground shield at OCM-3 only Basic Wiring Temperature SensorRelays MA OutputSynchronization DC Power Power ConnectionsAC Power Communicating VIA Computer Installing the Memory BACK-UP BatteryInstalling the Programmer Disconnect power before installing or replacing the batteryKeypad Start UPGeneral English Initial Start UPOCM-3 is asking which language you prefer to communicate LanguageF13 auto zero calibration 160 Completed 7ML19985AB01 P0 language English P1 dimensional units CentimetersF5 ddmmyyyy date October 12 114124-hr. time 114100 Enter new timeFundamental Checks OCM Units OperationMemory Security= constant Flow CalculationDisplay Absolute vs. ratiometricDamping For battery operation, set display lighting to off or auto» P6 * flow rate For battery operation, have relays energizing on alarmExample For relay » 20 mAFlow rate FAIL-SAFEFlow Rate and Totalizing Capacity LoggingViewing the data log Time and Date TemperatureBlanking Reset Emulation ModeAs normal 7ML19985AB01 Flow Velocity InputAuxiliary Head Input Voltage Input Current Input100% head 4 m, enter 5 m Diagnostic AidsDC Output Nominal target range Security access required‘D’ Parameter Listing VelocityOCM Keypad to mA output Enter security code Emulation mode‘F’ Parameter Listing OCM = centimetres ‘P’ Parameter ListingLinear Velocity = imperial million gallons per day Flowrate Volume= absolute = ratiometric Flow rate units GallonsOCM = 4-20 mA = 0-20 mA 7ML19985AB01 OCM OCM Units FixedVariable condition OCM ‘U’ Parameters for P3 Primary Element OCM = constant factor U1 = head U0 = exponent U1 = k factor P4 = 0 onlyReference Typical Weir Profiles Typical SHARP-CRESTED WeirsKhafagi Venturi Typical Parshall Flume Typical Leopold Lagco ‘U’ parameters required ‘U’ parameters calculated BS-3680 Rectangular Flume = crest width = Cv = crest height = Cd = crest length = a BS-3680 Round Nose Horizontal Crest Weir ¤ Refer to Operation \ Flow Calculation 7ML19985AB01 Cv = velocity coefficientBS-3680 Trapezoidal Flume BS-3680 U-Flume, P3 = BS-3680 U-FLUME = head H and p applied to C = crest width = C = crest height = Cp = crest lengthBS-3680 Finite Crest Weir = crest width He = effective head h + Kh = head Kh = 1 mm = Ce x 2⁄3 ⎯⎯√2⎯g x be x he1.5 Where q = flow rate= approach width = Ce = crest width = K b = crest height = gravitational accelerationBS-3680 Thin Plate Rectangular Weir U0 = notch angle Alpha U1 = Ce BS-3680 Thin Plate V-NOTCH Weir U0 = crest width b Rectangular Weir Contracted = hydraulic radius = slope of hydraulic gradient Based on the Manning FormulaRound Pipe U0 = maximum flume width, hmax PALMER-BOWLUS Flume U0 = maximum listed head, hmax Flume U0 = number of data points n, 4 to Universal Head vs FLOW, P3 =Flow, point A19 Flow, point A13 Head, point A14Flow, point A15 Head, point A16 Flow, point A17 Head, point A18U0 = channel width B U1 = area h Rectangular Area X Velocity = head, cm = flow velocity, cm/sec Trapezoidal Area X Velocity = channel top width, cm = head, cm = channel base width, cm = B b/d Where q = flow rate, l/sFor h ≥ d Modified Trapezoidal Area X Velocity U0 = base diameter D U1 = area h Channel Area x Velocity U0 = conduit diameter U1 = area h Circular Area X Velocity GULL-WING Area X VELOCITY, P3 = Gull Wing Area X Velocity EGG-SHAPED Area X VELOCITY, P3 = EGG-SHAPED Area X Velocity Typical open channel Universal Area X VELOCITY, P3 =A10 = Universal Area X VelocityArea Head OCM Maintenance Error Codes Serial printer Customer’sComputer 102 Protocol for the OCM-3 is as follows Baud rateRefer to Cvcc Instruction DB-9 connectorDB-25 connector Bipolar Current104 DateP35 = 7, print interval set for 7 minutes 105 Utilities Software Programmer Remote OCM-3 programmingRemote OCM-3 display Local display 106 107 Typical OCM-3Display value 00.000000 99.12399.123000 7ML19985AB01Response # = 0 through Content of P5109 Start data log down loadStop data log down load Computer Telephone lines Remote modem DB-25 connector 7ML19985AB01Standard modem Cable111 Establishing CommunicationConnect 112 Ending CommunicationRev