User’s Manual Model DM8 Vibration Type Density Meter IM 12T03A01-02E R IM 12T03A01-02E 3rd Edition
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i INTRODUCTION This manual describes the specifications, installation, operation, maintenance, and troubleshooting for the Model DM8 Vibration Type Density Meter. To use this manual correctly, read this manual thoroughly. For the Model VD6SM Sampling System, refer to IM 12T3S1-01E. Media No. IM 12T03A01-02E 3rd Edition : Jun.
ii For the safe use of this equipment Safety, Protection, and Modification of the Product • In order to protect the system controlled by the product and the product itself and ensure safe operation, observe the safety precautions described in this user’s manual. We assume no liability for safety if users fail to observe these instructions when operating the product.
iii Symbol Marks Throughout this user’s manual, you will find several different types of symbols are used to identify different sections of text. This section describes these icons. WARNING Indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury. CAUTION Indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury. It may also be used to alert against unsafe practices.
iv After-sales Warranty Do not modify the product. During the warranty period, for repair under warranty consult the local sales representative or service office. Yokogawa will replace or repair any damaged parts. Before consulting for repair under warranty, provide us with the model name and serial number and a description of the problem. Any diagrams or data explaining the problem would also be appreciated.
v Model DM8 Vibration Type Density Meter IM 12T03A01-02E 3rd Edition CONTENTS INTRODUCTION ...................................................................................................i For the safe use of this equipment ...................................................................ii After-sales Warranty ..........................................................................................iv 1. GENERAL .....................................................................
vi 2.2.2 3. INSTALLATION, PIPING AND WIRING.................................................... 3-1 3.1 3.2 3.3 3.4 4. Installation of Density Detector ....................................................................... 3-1 3.1.1 Mounting Density Detector ................................................................ 3-1 3.1.2 Sampling Unit for Vibration Type Density Meter ................................ 3-2 Installation of Density Converter ...................................
5.1 5.2 vii Daily Inspection/Maintenance ......................................................................... 5-1 5.1.1 Cleaning the Vibrator in the Detector ................................................. 5-1 5.1.2 Exchange of Desiccant in the Detector ............................................. 5-1 Troubleshooting ................................................................................................ 5-2 5.2.1 Checking the Vibrators....................................
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1-1 < 1. GENERAL > 1. GENERAL Density is one of the fundamental physical quantities required when the property or composition of a liquid sample is being determined in industrial processes. Especially, density measurement of a sample liquid is indispensable in many industries such as electric manufactures, chemical industries, oil refineries and food-related applications. The Model DM8 Vibration Type Density Meter is a higher reliable meter full of operation and maintenance functions.
1-2 1.1.2 < 1. GENERAL > Detector (1) General Purpose Detector Model VD6D Detector construction: Non-explosion protection, rain-proof construction Case material: Cast Aluminum alloy Case coating: Epoxy resin, baked finish Case color: Jade green (equivalent to Munsell 7.5BG4/1.5) Wetted part materials: Base: SUS316 Vibrator: SUS316 or Ni (Au Brazing: BAu·4) Measuring liquid temperature: –10 to 100 °C Measuring liquid pressure: 2 MPa G or less Maximum pressure: 4.
1-3 < 1. GENERAL > 1.1.
1-4 < 1. GENERAL > • Output format Measured data # * . * * * * _ * . * * * * _ * * * . * CR LF space space (Note) Data are output in the order of density (data converted into that at a reference temperature), density (at measuring temperature), and measuring liquid temperature. Hold data (data immediately before entering the mode) is output during the time of calibration or maintenance mode. However, holding is released immediately after calibration or maintenance mode.
< 1. GENERAL > Case construction: Coating color: 1-5 Dust and rain proof construction Door: Equivalent to Munsell 2.8GY6.4/0.9 Case: Equivalent to Munsell 2.0GY3.1/0.5 Coating finish: Baked finish epoxy resin Mounting: To panel, wall or 2-inch pipe Air purge connector: Rc1/8, Rc1/4, or 1/4NPT female is also optionally available Electrical connection: Five holes, 27 mm dia. Attached with four plastic waterproof plugs equivalent to JIS A15, and one plastic waterproof plug equivalent to JIS A20.
1-6 < 1. GENERAL > 1.2 1.2.
< 1. GENERAL > 1.3 1.3.
1-8 < 1. GENERAL > Sanitary Use Detector Model VD6DS Unit : mm 246 153 ø110 104 100 192 Gland 166 ø116 Sample Output * ø74 2-inch Pipe (Horizontal or Vertical) 345 58 73 103 Sample lnlet * Electrical Wiring Port G3/4 200 ø160 IM 12T03A01-02E 146 * The ends of sample inlet and outlet are connected with 1/8-inch pipe in welding. The pipe may be removed by loosing the gland.
1-9 < 1. GENERAL > 1.3.2 Converter Model DM8C 183 138 116 272 288 240 Unit: mm 14 Mounting bracket (applicable with any mounting method to panels, walls or pipes) 200 Wiring port holes (5-ø27) (with rubber plugs) 34 34 34 34 23 31 35 Mounting panel thickness Max. 12 Purge air inlet Rc1/8 * Pipe mounting bracket Purge air outlet (with seal sheet) Mounting pipe (2-inch pipe) *: When option code is specified, Rc1/4 or 1/4 NPT female connector is attached.
1-10 1.3.3 < 1. GENERAL > Special Cable Model DM8W Unit : mm Density converter Density detector 130(from A) B4 WHITE 60(from A) GRAY B5 110(from A) (from B)100 A5 GREEN 60 (from A) ø15.8 IM 12T03A01-02E (from B)90 60(from A) (Note) Cable length is specified by the suffix code of “-L e.g.
1-11 < 1. GENERAL > 1.4 1.4.1 Cautions in Handling Flameproof, Explosionproof Instruments Outline of Explosionproof Instruments Specifications of “Explosionproof Instruments” conform to the regulations of relevant public organizations. Model DM8 Vibration Type Liquid Density Meter consists of a density detector and a density converter. Model VD6DF density detector, explosionproof instrument, can be installed in hazardous area where explosive gases may be generated.
1-12 1.4.3 < 1. GENERAL > Installation Area and Ambient Conditions Model VD6DF density detector can be installed in hazardous area where specified gases are present. However, do not install the detector at the place where explosive gases may be continuously present, and in which the gas concentration is continuous or for long period, equal to or more than, the lowest gas explosion limit. Environmental conditions at the installation site are very important to the detector.
< 2. PRINCIPLES OF OPERATION > 2. PRINCIPLES OF OPERATION 2.1 Measuring Principle 2.1.1 2-1 Density Detector Model VD6D Density Detector is a vibration type density meter. Measuring principle is that the lateral free oscillation of a pipe is a function of the density of the liquid contained in the pipe. Assuming that the pipe is filled with a liquid as shown in Figure 2.1, the lateral free oscillation of the pipe can be shown as the following equation: D1 l D2 Joint Joint Figure 2.
2-2 2.1.2 < 2. PRINCIPLES OF OPERATION > Density Converter The density converter computes the liquid density using the oscillation frequency signal and voltage of the temperature. Each value of l, E, ρ1, D1, D2 or rx in equation (1) is a function of liquid temperature, hence the value of fx is also a function of temperature. To obtain the correct density, the factors A(t) and B(t) depending temperature should be previously compensated for the temperature as follows.
2-3 < 2. PRINCIPLES OF OPERATION > 2.2 2.2.1 Main Components Density Detector Figure 2.2 is a schematic diagram of the density detector. As shown in the figure, the density detector consists mainly of a vibrator assembly, a capacitance pickup electrode, and an amplifier. Sample Vibrator Pick-up electrode Preamplifier Density signal Temperature signal Temperature measuring element Piezo-electric element Vibrator cross sectional view of Density Detector Figure 2.
2-4 2.2.2 < 2. PRINCIPLES OF OPERATION > Density Converter Figure 2.3 is a block diagram of the density converter. As shown in the diagram, the density converter receives the density signal (frequency) Fρ and temperature signal (voltage) VT from the density detector and finally outputs a 4 to 20 mA analog signal and 0 to 1 V DC signal corresponding to the liquid density converted to that at reference temperature.
3-1 < 3. INSTALLATION, PIPING AND WIRING > 3. INSTALLATION, PIPING AND WIRING Model DM8 vibration type density meter consists of a density detector and a density converter. The density detector is generally installed in field and sampling piping is made to conduct measuring liquid. The density converter is generally installed in the vicinity of the density detector. It must not be installed in hazardous area.
3-2 < 3. INSTALLATION, PIPING AND WIRING > (2) Bracket Mounting This bracket is not the pipe mounting bracket. Release the four bolts (with spring washers) to remove the pipe mounting bracket from the detector. Using the four bolts and spring washers, fix the detector on the bracket as shown in Figure 3.4. Figure 3.3 shows position of holes to be drilled on the bracket. Unit: mm 70 ±0.2 4-ø9 Holes 40 ±0.2 Figure 3.3 Position of Holes on the Bracket Density detector Figure 3.4 3.1.
3-3 < 3. INSTALLATION, PIPING AND WIRING > (1) Flow Diagram Figure 3.5 shows a flow diagram of a typical sampling equipment. Model VD6SM sampling unit of Yokogawa is also designed according to this diagram. FM TI PI BV1 DD NV4 SAMPLE IN F a NV1 NV2 NV3 SAMPLE OUT b a a' V1 V2 STEAM IN b' a' ST1 CONDENSATE OUT Figure 3.5 Element specifications F: Strainer body; SUS316 Element; SUS316, or Ni (option) PI: Pressure gauge, 0 to 1MPa or 0 to 2MPa, SUS316 TI: Thermometer.
3-4 < 3. INSTALLATION, PIPING AND WIRING > Density meter sampling unit Anchor bolt Drain pit Concrete base Figure 3.6 Installation Example for Sampling Unit (Model VD6SM) (2) Note of Designing a Density Meter Sampling Unit • Minimize liquid pipe length to improve response. • Design the piping not to allow air bubbles to remain in the pipe which may cause an error. • Piping should not have sharp bending where solids may accumulate. • Maintenance such as cleaning should be made easily.
< 3. INSTALLATION, PIPING AND WIRING > 3-5 (4) Removing a Packing Sheet for Transportation from the Density Detector The vibrator is fixed to the amplifier case to avoid being damaged during transportation. Remove the rubber sheet used for the fixing. The rubber sheet is inserted between the case and the coupler of the vibrator assembly. Remove the sheet according the steps below. For component names, refer to the section 4.1.1. (a) Remove the lock with a hexagonal bar wrench.
3-6 < 3. INSTALLATION, PIPING AND WIRING > 3.2 3.2.1 Installation of Density Converter Installation Area The density converter should be installed in the place described below; (1) The vicinity of the sampling unit where maintenance or calibration is made easy. The density converter is designed dustproof and rainproof structure so that it can be installed outdoors.
< 3. INSTALLATION, PIPING AND WIRING > 3-7 (1) Panel Mounting The pipe mounting bracket should be removed from the converter before panel mounting. Panel cutout dimensions are shown in Figure 3.9. Before inserting the converter into front of the panel, remove the clumping brackets from both sides of the converter case. After the case is inserted into a panel, remount the clumping brackets on the same pace to hold the converter on the panel. Figure 3.10 illustrates that the converter is mounted on a panel.
3-8 < 3. INSTALLATION, PIPING AND WIRING > (2) Wall Mounting Remove the pipe mounting bracket from the converter before wall mounting. Make two holes for 8 mm screws in a wall as illustrated in Figure 3.11. Unit: mm 222 2-M8 Screws Figure 3.11 Holes for Wall Mounting Figure 3.12 Wall Mounting Using two mounting brackets, mount the converter on the wall (see Figure 3.12).
< 3. INSTALLATION, PIPING AND WIRING > 3-9 (3) Pipe Mounting Mounting bracket is applied to the pipe of nominal size 50A (diameter 60.5 mm). As shown in Figure 3.13 mount the converter on the vertical pipe (inclination causes no problem). Figure 3.
3-10 < 3. INSTALLATION, PIPING AND WIRING > 3.3 Piping The vibration type density meter requires the following piping; (1) Sample liquid conduit (2) Air piping for maintenance (3) Steam piping (4) Piping for air purge Sample liquid conduit is a pipe to conduct measuring liquid to the density detector. Air piping for maintenance is to obtain air to blow away liquid from the vibrator at maintenance (vibrator cleaning, calibration with standard solution).
< 3. INSTALLATION, PIPING AND WIRING > Sampling unit 3-11 Main pipe Sampling line Sludge is likely to collect here. Figure 3.15 3.3.2 Example of Wrong Piping Air Piping for Maintenance When cleaning the vibrator or calibrating the meter with standard solution, blow away liquid from the vibrator by air pressure. Air should be clean and dried with 0.3 to 0.5 MPa G.
3-12 < 3. INSTALLATION, PIPING AND WIRING > Heat insulating material Trace pipe Sampling line Figure 3.17 Steam Tracer Pipe Steam trap Sampling unit Drain pit Figure 3.18 3.3.4 Piping at Steam Trap Discharge Outlet Piping for Air Purge If the density converter is installed in dusty environment, air purging is recommended. Air purge should be performed continuously by clean dried air with pressure of 50 kPa G.
< 3. INSTALLATION, PIPING AND WIRING > 3.4 3-13 Wiring The vibration type density meter requires the following wirings: (1) Wiring between analog output signal (2) Wiring for analog output signal (3) Wiring for digital output signal (10 m or less length is recommended). (4) Wiring for contact output for abnormal status (5) Wiring for power supplying (6) Wiring for grounding Figure 3.19 is a diagram of these wirings. Detector Special cable Converter A2 RED A2 N.
3-14 < 3. INSTALLATION, PIPING AND WIRING > Figure 3.21 shows terminal arrangement of the density detector. Terminals A2 A3 A4 Figure 3.21 3.4.1 A5 A6 B4 B5 B4 B5 A2 A3 A4 A5 A6 Function Output Frequency Temperature Sensor Power Supply for Pre-amp Impressed Voltage for Pick-up Electrode Earth Terminal Terminal Arrangement of Density Detector Wiring between Detector and Converter This wiring is to be carried out with special cable of specified length.
< 3. INSTALLATION, PIPING AND WIRING > Figure 3.23 Wiring to Density Detector Terminals 3-15 Figure 3.24 Spanner for Open/ closing Terminal Box Cover Cable Terminal box case Be sure to screw in at least 12 mm (5 threads) Lock nut G3/4 screw (TIIS explosionproof) 3/4NPSM (FM explosionproof) Explosionproof flaxible fitting Figure 3.25 Explosionproof Flexible Fitting (Connection to Density Converter) The density converter is installed in field or indoors (control room).
3-16 3.4.2 < 3. INSTALLATION, PIPING AND WIRING > Wiring for Analog Output Signal Output signal of 4 to 20 mA DC output (load resistance 550 Ω or less) and 0 to 1 V DC (load resistance 250 kΩ or more) are provided. Carry out either or both of wirings as necessary. Shielded 2-conductor (for one signal) or 4-conductor (for two signals) cable are used for wiring. For connecting the cable to the converter, remove the sheath of conductor about 50 mm from its end, and attach a solderless lug for M4 screw omit.
< 4. OPERATION > 4. OPERATION 4.1 Component Names and Function 4.1.1 4-1 Density Detector Vibrator assembly Case Terminal box Capacitance pickup electrode Oscillation amplifier Terminal box cover Lock Coupler Vibrators Cover Figure 4.
4-2 < 4. OPERATION > 4.1.2 Density Converter Data Display: Function No. and data are displayed. Front door Function No. display Data display Fastener (Nyratch) Internal assembly fixing screw (for transportation) ,1&5 Ÿ NH\ Increases the number of a flashing digit. 6(7 NH\ Used to enter a displayed data. Data sheet 6+,)7 Ź NH\ 3UHVVHG WKL NH\ GLVSOD\HG number flashes.
4-3 < 4. OPERATION > 4.2 4.2.1 Operation Operation Mode Operation of the Model DM8 vibration type density meter ruled by the mode as shown in Table 4.1. Measuring mode (DSPL), calibration mode (CAL) and maintenance mode (MAINT) are transferred with the mode transfer switch. Table 4.1 MODE SW Measuring Operation Modes and Function No. FUNCTION NO.
4-4 < 4. OPERATION > Digital signal (Note 1) Measuring mode (DSPL) Measured Measured value value Measured value Maintenance mode (1) (MAINT) (1) Measured value Hold (1) Hold (2) Hold Hold Hold Transfer to Calibration mode Calibration mode (CAL) Analog signal Calibration start While in calibration computation Output stop (Note2) Calibration end Calibration mode function No. transfer or waiting for mode transfer Measured value Measured value Function No.
4-5 < 4. OPERATION > Function No. ‘7’: Sets density of calibration solution 2 Density data (g/cm3) for the 2nd calibration (calibration solution 2) of two-point calibration can be input. As a rule, the input density is data at the same reference temperature as that of ‘4’. (Note) If relation between temperature and density is well known, a density at a temperature can be input.
4-6 < 4. OPERATION > Function No. ‘7.’: Sets high limit of the output range Sets a high limit density value (g/cm3) of an analog output range. (Note) Difference between high and low limit value should be 0.05 g/cm3 or more. If an inadequate value is set, the function No. returns to ‘6.’ operations of ‘6.’ and ‘7.’ are related; when setting is made at ‘6.’ setting should also be made at ‘7.’. Function No. ‘8.
4-7 < 4. OPERATION > 4.3 4.3.1 Preparation for Measurement Check for Piping Check the following points. (1) Is the pressure difference 100 kPa or more between both sampling tap? (2) Is the diameter of the sampling pipe appropriate? Is length of the inlet pipe too long? (Note) The sample inlet pipe is usually JIS 15A or Sch 40 to 80 stainless steel pipe. The pipe length between sampling tap and the detector should be 10 m or less.
4-8 < 4. OPERATION > (5) Fully open “BV1” and “NV4” and half open “NV1” in the sampling unit. Close ‘drain’ valve opened in (3). Gradually open the ‘tap’ valve located on the sample inlet conduit. As sample begins to flow out of the ‘drain’ valve on the sample return conduit, fully open the ‘stop’ valve and fully close the ‘drain’ valve when no retaining air is found in the liquid. (6) Open “NV2” to exhaust retaining air in the pipe.
4-9 < 4. OPERATION > 4.3.6 Pressure Compensation Pressure compensation means to compensate the shift generated by measurement under operating pressure. The compensation should be carried out as necessary only for calibration under atmospheric pressure. Measured value is affected up to +0.00005 g/cm3 by 100 kPa pressure variance. Therefore, for liquid under pressure approximating to the atmospheric pressure calibrated value under atmospheric pressure can be used.
4-10 < 4. OPERATION > The one-point calibration is equal to that omitting the 2nd calibration two-point calibration, so, the twopoint calibration using standard solution and sample liquid is described as follows. Since the following is described assuming that the density converter is installed in the vicinity of the density detector, for the connector installed away from the detector, please edit the manual for it and carry out the calibration according to the manual. 4.4.
4-11 < 4. OPERATION > (Note 2) The density value after calibration doesn’t always coincide with the density of the standard solution 1 even if they are compared in the same temperature. Especially when the solution temperature during calibration largely different from the reference temperature an error is apt to occur. However, the error is usually within allowable range, if it is too large, examine each set value. (8) The first calibration is finished by (7).
4-12 < 4. OPERATION > 4.5 4.5.1 Operation Operation Procedure Start the density measuring system, and monitor operating conditions for a while to confirm that there is no abnormality. Adjustment for the density measuring system during operation is unnecessary, however, daily check of liquid flow rate and pressure is preferable. When the steam tracing pipe is installed in the sampling unit, do not heat the detector. If an error indication is displayed, make a countermeasure immediately.
5-1 < 5. MAINTENANCE > 5. MAINTENANCE 5.1 Daily Inspection/Maintenance 5.1.1 Cleaning the Vibrator in the Detector Dirt particles may be deposited on the inner wall of the vibrator pipe, depending upon the nature of the process liquid. This can cause an error. Clean the pipe at regular intervals in the following manner. (1) Close valves BV1 and NV4 and open NV2 and NV3. (2) Connect the air pipe to the outlet of the needle valve NV2.
5-2 < 5. MAINTENANCE > 5.2 Troubleshooting Experiences are required for repair of the vibration type density meter; after parts are replaced, adjustment may be necessary. If trouble occurs, as a rule, repair should be made by Yokogawa. In this case, detailed information on abnormal phenomena will be effective for speedy recovery. Searching method for abnormality is explained below.
5-3 < 5. MAINTENANCE > 7HUPLQDO Box Vibrator output wavefarm between B4 and B5 when density detector is operating normally.
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Customer Maintenance Parts List Model VD6D, VD6DF, VD6DS Density Detector Item 1 2 3 4 5 Part No.
2 Accessories Assembly Item Part No. Qty 1 2 3 4 5 K9000PQ L9827AR K9000NB L9827AE E9135GZ 1 1 1 1 1 6 7 K9324PC K9003NG 1 1 CMPL 12T3E1-01E Description Accessories Assembly Brush Injector Allen wrench Spanner Desiccant (2 packs) O-Ring Set (used for item 6 and 7 in page 1) 5th Edition : Apr.
Customer Maintenance Parts List Model DM8C Density Converter Item Part No. Qty Description *1 *2 *3 4 K9000ZM K9000VV K9000YJ K9000YH K9000YR 1 1 1 1 1 Spare Display Unit (for style *B) Display Board Assembly (for style *C) CPU Board Assembly Main Board Assembly Cable Assembly (7 pins) 5 6 *7 K9000YQ K9141TV K9000ZE 1 1 1 Cable Assembly (5 pins) Fuse (250 V, 3 A) Transformer Assembly *: Do not change these parts, call service personnel.
2 Accessories Assembly Item Part No. Qty 1 2 3 4 B1003JZ L9811FP K9141TV G9612BC G9612BE 1 4 1 1 1 CMPL 12T3H1-01E Description Cable Gland Cable Gland Fuse (250 V, 3 A) Connector Rc1/4 (for /AP1) Connector 1/4NPT (for /AP2) 6th Edition : Mar.
i Revision Information Title Manual No. : Model DM8 Vibration Type Density Meter : IM 12T03A01-02E Jun. 2012/3rd Edition Page layout changed by InDesign P.4-9 Figure 4.5 Flow Diagram added, P.5-1 Figure 5.2 Flow Diagram added, CMPL 12T3H1-01E revised to 6th edition. Apr. 2009/2nd Edition P.1-4 Standard Accessories, P.1-5 DM8C Style B to C, change of CMPL 12T3E1-01E P.2 Item 3 and CMPL 12T3H1-01E P.1 Item 1. Dec.
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