Resumen del contenido incluido en la página 1
@a FTBSOO Series
Q
a Low Flowrate Meters
(i%%i OPerator’s Manual
Resumen del contenido incluido en la página 2
ka OMEGKj Am D.aaw.4 Taek,.l.#hm c..pmmy Servicing USA and Canada: Call OMEGA To il Free USA Canada One Omega Drive, Box 4047 976 Bergar Stamford, CT 06907.0047 Lava1 (Quebec) H7L 5Al Telephone: (203) 359.1660 Telephone: (514) 856-6928 FAX: (203) 359-7700 FAX: (514) 856-6886 Sales Service: l-800-826-6342 / 1-800-TC-OMEGA-‘M Customer Service: l-800-622-2378 / l-80%622~BESP Engineering Service: l-800-872-9436 / I-800-USA-WHENSM TELEX: 996404 EASYLINK: 62968934 CABLE: OMEGA Servicing Europe: United
Resumen del contenido incluido en la página 3
TABLE OF CONTENTS FTB500 SERIES FLOWMETERS PAGE SECTION SECTION 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . .I . . 1.1 Description ..................... . . I.2 Available Models ................. ............... . . I.3 Theory of Operation ......... . . . 1.3.1 Performance Characteristics . . . . 1.3.2 Viscosity Effects ................. ... . . . 1.3.3 Viscosity Calibration and UVC Curves 6 . ........ , ................. SECTION 2 INSTALLATION . 6 2.1 Unpacking ..........
Resumen del contenido incluido en la página 4
SECTION 1 INTRODUCTION 1.1 DESCRIPTION The OMEGA@ FTB500 Series Low Flowmeters offer extremely accurate low flow measurement of liquids and gases. They utilize a pelton wheel-like rotor whose motion is converted into a pulse output proportional to flow by a pickup coil. They come with an integral signal conditioner, powered by either 15-35 VDC or 115 VAC (optional) to provide amplified frequency and analog output. The signal conditioner corrects for the inherent zero off- set of the flowmeter pu
Resumen del contenido incluido en la página 5
1.3 THEORY OF OPERATION A simplified block diagram of the FTB500 Mini Flow Signal Conditioner is shown in Figure 1-I. SENSITIVITY +v FTBBOO SIGNAL pcA_,,B CONDITIONER TURBINE FLOWMETER= MAIN CHASSIS CAPACITOR COUPLED FREQ. TO CONVERTER - - ANALOG OUTPUT OUTPUT AMP. Figure l-l. Block Diagram The basic operation of the system is as follows: The frequency signal from the flowmeter is connected to the FTB500 with a twisted pair shielded cable. The signal enters through the SENSITIVITY control which
Resumen del contenido incluido en la página 6
The signal entering the frequency to analog converter is passed through a combination of divide by N and DIP switch matrix. The output is chosen whose pulse rate is between 75 and 150 Hz at the maximum flow rate to be measured. This scaled pulse rate is fed into a precision monostable cir- cuit. The output of the monostable is then filtered into an analog voltage that is proportional to flow. The output amplifier will take this voltage and perform either a voltage to voltage amplifier or voltage
Resumen del contenido incluido en la página 7
lL / UN LINEARIZED OUTPUT FLOW RATE (GPM) Figure 1-2. FTBSOO Output Characterlstlcs Diagram LINEARIZED 8 5 90 UNLINEARIZED ! 7 .80 f u 1.00 I_7 10 50 100 % OF MAX IMUM FLOWRATE Figure 1-3. Normalized FTBIOO Calibration Curve 4
Resumen del contenido incluido en la página 8
Over the linear flow range, the input/output characteristics takes the form of: Equation 1 Frequency = C, x Flowrate-C, The FTB500 Series Turbine Meter requires the use of a linearization con- ditioner available in all OMEGA instrumentation. Accuracies of *l% of reading are typical after initial correction for offset. Better accuracies ap- proaching *2% are possible using smart transmitters which can store the entire characteristics of the FTB500 Series Turbine Meter. The K-Factor is the number
Resumen del contenido incluido en la página 9
1.3.2 Viscosity Effects An ideal flowmeter may be defined as one in which the output is solely a function of the fluid flow being measured. Real flowmeters display dependencies on secondary fluid properties, such as viscosity temperature, and/or pressure. These effects tend to obscure or degrade the precision of the flow measurement. In very few flowmeter designs, the viscosity dependency is well understood and given suitable documentation, may be compensated for. The OMEGA instruments are among
Resumen del contenido incluido en la página 10
2.2 OPERATION Perform any purging of piping with spool piece in place. Once completed, install the flowmeter and connect cabling to pickup coil. With the FTB500 Mini Flow Signal Conditioner properly installed and calibrated, verify the following performance. With the power ON and no flow through the flowmeter, there should be no pulse output from the unit. To verify this, connect either a digital Frequen- cy Counter or an AC voltmeter. If using a Digital Frequency Counter, the display should dis
Resumen del contenido incluido en la página 11
The piping configuration immediately preceeding and following the flowmeter is termed the meter run. METER RUN -In general, the meter run should be chosen to have the same inner diameter as the meter bore. A minimum of IO pipe diameters of straight pipe upstream and 5 pipe diameters downstream are required. Where this optimum line configuration can not be implemented, it is ad- visable to install a flow straightener properly positioned upstream of the flowmeter. Orientation is not a critical fac
Resumen del contenido incluido en la página 12
It is common to transmit the low level output signal from the flowmeter several hundred feet through a shielded, twisted pair instrument cable. Where a noisy environment is suspect, it is recommended that a pre- amplifier be installed on or near the flowmeter to assure the preservation of flow information from the flowmeter to the electronic measuring system. Suitable accessory models are available from the manufacturer. 2.5 INSTALLATION OF THE FTB500 MINI FLOW SIGNAL CONDITIONER The FTB500 sho
Resumen del contenido incluido en la página 13
-- I -\- 7x A I 1 0 To PICKUPCOIL : i I 1 ’ :, B ’ :, 0 _ .- -- Lo + SIGNAL TERMINAL @ ANALOG OUTPUT BLOCK 1 RETURN (STANDARD) - 1 0 + SIGNAL @ PULSE OUTPUT _ COMMON 1-P OPTION) 0 F(TEBT) @ - DC VOLTAGE INPUT TERMINAL BLOCK 2 1234567 8 NOTE THE FTB500 IS EQUlPPED WITH AN INTEGRAL CALIBRATION SIGNAL. TO INJECT THIS TEST SIGNAL, INSTALL A JUMPER FROM TERMINAL 8 TO TERMINAL 1. Figure 2-3. DC Input Installation Wiring Diagram 10
Resumen del contenido incluido en la página 14
Ayy==+--~ Xl PICKUP COIL TERMINAL BLOCK 1 F(TEST) @ u IIBVAC E (NEUTRALS TERMINAL 50160 Hz BLOCK 2 INPUT NOTE THE FTB500 IS EQUIPPED WITH AN INTEGRAL CALIBRE TO INJECT THIS TEST \TlON SIGNAL. SIGNAL, INSTALL A JUMPER FROM TERMINAL 8 TO TERMINAL 1. Figure 24. 115VAC Input Installation Wiring Diagram 11
Resumen del contenido incluido en la página 15
Connect the line power and ground to appropriate terminals. The line power should be an ‘instrument grade ’ line whose various loads do not contain solenoids, valves or other similar transient producing load which might adversely affect the operation of the system. Connect the cabling to the pulse output and to the inputs of the final measurement system. Observe same precautions listed for interconnecting cabling. SECTION 3 CALIBRATION 3.1 INTRODUCTION In general, all FTB500 flowmeter systems su
Resumen del contenido incluido en la página 16
3.3 l7I CONFIRM FTBSOO SIGNAL CONDITIONER OFFSET 1. Connect frequency counter to the offset frequency test point of the unit. 2. Inject the TEST frequency and observe that the frequency equals 10 x F(OS). For analog, go to Section 3.4. For pulse, continue to step 3. 3. Connect frequency counter to the output of the unit and with an in- jected TEST frequency, verify that the output frequency equals F(OUT) in the equation stated above. 3.4 CALIBRATION OF FTBBOO ANALOG OUTPUT 3.4.1 Set Up The sig
Resumen del contenido incluido en la página 17
where: F(TEST) = test frequency used = offset frequency F(OSl F(MAX) = the flowmeter output frequency at R(MAXl when at the reference condition at which the relation with F(MAX) was defined. = in units of readout, ifi, PULSE/GAL K Factor = varying component of analog output. For example, SPAN 16 mA for 4 to 20 mA output, 5V for 0 to 5V output ZERO = fixed offset component of analog output. For example, 4 mA for 4 to 20 mA output, OV for 0 to 5v output. 1. The Range Adjustment is accomplished by
Resumen del contenido incluido en la página 18
FOR CURRENT OUTPUT OPTION ONLY 3. Connect a digital milli-ammeter or equivalent, across the current out- put terminals. 4. Adjust “ZERO” potentiometer (refer to Figure 3-l) for desired “ZERO” current (i.e., 4 mA). 5. Inject the test frequency while adjusting “SPAN” potentiometer (refer to Figure 3-l) so the current equals to SET (SPAN). 6. Repeat steps 4 and 5 until no change is observed. FOR VOLTAGE OUTPUT OPTION ONLY 7. Connect a digital voltmeter across the voltage output terminals. 8. Inject
Resumen del contenido incluido en la página 19
CORRECT OR IENTAT ION OF ROTOR WHEN LOOK ING DOWN FROM TOP -8 OW FL FL OW - DETA IL OF ROTOR WELO- F igure 4 -1. S tandard Ba ll Bear ing Cu ta way D iagra m 16
Resumen del contenido incluido en la página 20
1. The FTB500 Flow m eter m ust be held in place by a vise. Me ter orien- tation should be such that the threaded plug is facing upwards. 2. Using a screwdriver and turning counter clockwise, break the seal and re move the plug. 3. Using tweezers or needle nose pliers, slowly pull the insert out, while taking care not to da m age the shaft or lose the thrust stop. 4. Remove the rotor by using a pair of tweezers. 5. Remove the shaft asse m bly with s m ooth needle nose pliers. Care should be take
