Page 4
[no content intended for this page - proceed to next page]...
Page 5
Preface Information Paragraphs Note: These paragraphs provide information that provides a deeper understanding of the situation, but is not essential to the proper completion of the instructions. IMPORTANT: These paragraphs provide information that emphasizes instructions that are essential to proper setup of the equipment.
Page 6
Environmental Compliance Waste Electrical and Electronic Equipment (WEEE) Directive GE Measurement & Control Solutions is an active participant in Europe’s Waste Electrical and Electronic Equipment (WEEE) take-back initiative, directive 2012/19/EU. The equipment that you bought has required the extraction and use of natural resources for its production. It may contain hazardous substances that could impact health and the environment.
Chapter 1. Calibration Chapter 1. Calibration 1.1 Introduction Calibrating the Model DF868’s analog outputs and inputs is explained in this chapter. In addition, testing the optional totalizer/frequency and alarm relay outputs is discussed. The following specific topics are included: • calibrating the built-in Slot 0 analog outputs •...
Chapter 1. Calibration 1.3 Calibrating the Analog Outputs Every Model DF868 flowmeter includes two built-in analog outputs (A and B) at terminal block , which is Slot 0 designated as . Both the zero-point and full-scale values for each output must be calibrated. After calibrating the outputs, which have a resolution of 5.0 A (0.03% full scale), their linearity should be tested.
Chapter 1. Calibration 1.3.1 Accessing the Calibration Menu Terminal Block (Option Card) Ammeter – Figure 2: Ammeter Connection (Output A) [CAL] 1. Press the key to enter the Calibration Program. [Fx] 2. Press to calibrate the desired slot. (The option bar will include a slot listing for each installed option card.) [Fx] 3.
Chapter 1. Calibration 1.3.3 Calibrating the High End of the Output Range [F2] 1. Press to calibrate the high end of the output range. [F1] [F2] DOWN [F3] 2. Press to adjust the ammeter reading , until a 20 mA reading is achieved. If you press Numer [ENT] , enter the numeric value and press...
Chapter 1. Calibration 1.4 Calibrating the Analog Inputs Analog inputs may be added to the Model DF868 flowmeter by installing an Analog Inputs Option Card in one (or more) of the six expansion slots. The option card contains two analog inputs, which are designated as A and B. Each of the inputs must be calibrated at both the zero-point and full-scale values.
Chapter 1. Calibration 1.4.1 Accessing the Calibration Menu [CAL] 1. Press the key to enter the Calibration Program. [Fx] 2. Press to calibrate the desired slot. (The option bar will include a slot listing for each installed option card.) [F1] 3.
Chapter 1. Calibration 1.4.4 Accessing the Calibration Menu (cont.) 1.4.5 20 mA Option = [F4] 1. Connect the 20 mA current source to the currently selected analog input, as shown in Figure 3 on page 5. [F1] [F2] ANALOG INPUT 2.
Chapter 1. Calibration 1.5 Calibrating the RTD Inputs Calibrating an RTD option card involves a slightly different procedure than for other analog input cards. However, you access the card in the same manner. 1.5.1 Accessing the Calibration Menu [CAL] 1. Press the key to enter the Calibration Program.
Chapter 1. Calibration 1.6 Alarms Option Card Alarm relays may be added to the Model DF868 by installing an Alarms Option Card in one (or more) of the six expansion slots. Each option card includes three alarm relays, which are designated as A, B, and C. To test the alarm relays, connect an ohmmeter to the option card terminal block as shown in Figure 4 below.
Chapter 1. Calibration 1.6.2 Testing the Alarm Relays Note: The procedure for testing Alarm Relay A Alarm Relays B and C is identical to that for testing . However, make sure that the ohmmeter is connected to the desired normally-open or normally-closed contact of the currently selected relay.
Chapter 1. Calibration 1.7 Totalizer/Frequency Option Card Totalizer/Frequency outputs may be added to the Model DF868 by installing a Totalizer/Frequency Option Card in one (or more) of the six expansion slots. Each option card includes four outputs, which are designated as A, B, C and D. To test the outputs, connect a frequency counter to the card’s terminal block as shown in Figure 5 below.
Chapter 1. Calibration 1.7.3 Entering Pulse Number 5. Enter the number of pulses desired (between 1 and 10,000) and press the [ENT] key. That number of pulses will then be output at the specified frequency. 6. Repeat steps 3, 4 and 5 to test all four of the frequency/totalizer outputs. If any of the outputs fails to pass the test, contact the factory for assistance.
Page 21
Chapter 1: Calibration SLOT0 SLOT1 SLOT2 SLOT3 SLOT4 SLOT5 SLOT6 Slot x (Option Card) Slot 0 Outputs (TB I/O) Slot x Inputs (Analog Inputs) Slot x Outputs (Alarms) ANALOG OUTPUT ANALOG INPUT ALARMS 4 mA 20 mA TEST EXIT aLOW aHIGH 4 mA 20 mA...
Chapter 2. Error Codes and Screen Messages Chapter 2. Error Codes and Screen Messages 2.1 Introduction The Model DF868 ultrasonic flowmeter is a reliable, easy to maintain instrument. When properly installed and operated, as described in the Startup Guide, the meter provides accurate flow rate measurements with minimal user intervention.
Chapter 2. Error Codes and Screen Messages 2.2 Error Codes E0: No Error Problem: No error condition currently exists. Cause: This message appears briefly to confirm that the response to another error message has corrected the problem. Action: No action is required. E1: Low Signal Problem: Poor ultrasonic signal strength or the signal exceeds the limits entered via the User Program.
Page 25
Chapter 2. Error Codes and Screen Messages E5: Amplitude Error Problem: SETUP The signal amplitude exceeds the limits programmed in the submenu of the User Program. Cause: Excessive levels of an attenuating gas, such as CO , are present in the flowcell. Solid or liquid particulates may be present in the flowcell.
Page 26
Chapter 2. Error Codes and Screen Messages E11: Poor Signal Problem: This message indicates a poor signal. Cause: The shape of the processed signal is not good enough to formulate a flow measurement. Action: Check the pipe and setup parameters and the transducer connections. The process may not include enough two-phase content —...
Chapter 2. Error Codes and Screen Messages 2.3 Screen Messages A variety of messages may appear on the display screen during the performance of a task. Since the error codes have already been discussed in this chapter and the locator bar messages are discussed in detail in Chapter 3, Operation, of the Startup Guide, they will not be repeated here.
Page 28
Chapter 2. Error Codes and Screen Messages Table 2: Screen Messages Message Meaning Log hasn’t started! hit key When in the LOG menu, this message indicates that the log has not yet started. OK, settling The measurement has not stabilized. Wait before taking a reading. Outside limits, When in the CAL menu, this message indicates that the calibration of the analog output is value rejected.
Chapter 3. Diagnostics Chapter 3. Diagnostics 3.1 Introduction This chapter explains how to troubleshoot the Model DF868 if problems arise with the electronics console, the flowcell, or the transducers. Indications of a possible problem include: • display of an error message on the active display screen •...
Page 30
Chapter 3. Diagnostics 3.2 Displaying Diagnostic Parameters (cont.) displays the Tdown parameter, as shown in the following prompt. [F1] For example, pressing [Fx] Press the [ or [ keys and the appropriate key to display a different (Ch1) label SITE EXIT...
Chapter 3. Diagnostics Table 3: Available Diagnostic Parameters (cont.) Option Bar Screen Display Description Good CNTdn Counts down Displays automatic gain control setting for the N.A. N.A. downstream signal. P#up UP +- Peak Displays signal peaks for the upstream transducer. 100-2300 <100 or >2300...
Chapter 3. Diagnostics 3.4 Flowcell Problems If preliminary troubleshooting with the Error Code Messages and/or the Diagnostic Menu indicates a possible flowcell problem, proceed with this section. Flowcell problems fall into two categories: • liquid problems • pipe problems. Read the following sections carefully to determine if the problem is indeed related to the flowcell. If the instructions in this section fail to resolve the problem, contact the factory for assistance.
The accuracy of the flow rate measurements is no better than the accuracy of the programmed pipe dimensions. For a flowcell supplied by GE, the correct data will be included in the documentation. For other flowcells, measure the pipe wall thickness and diameter with the same accuracy desired in the flow rate readings. Also, check the pipe for dents, eccentricity, weld deformity, straightness and other factors that may cause inaccurate readings.
Chapter 3. Diagnostics 3.5.1 Wetted Transducer Problems (cont.) 3. INTERNAL DAMAGE: An ultrasonic transducer consists of a ceramic crystal bonded to the transducer case. The bond between the crystal and the case, or the crystal itself, may be damaged by extreme mechanical shock and/or temperature extremes.
Chapter 4. Parts Replacement Chapter 4. Parts Replacement 4.1 Introduction The electronics console of the Model DF868 has been designed to permit easy on-site upgrades and parts replacement. See Figure 8 on page 35 and Figure 9 on page 36 for details of the standard DF868 electronics console assembly. The instructions in this chapter, along with a few common tools, are all that is required to perform the following tasks: •...
Chapter 4. Parts Replacement 4.2 Fuse Replacement If it has been determined that the fuse in the Model DF868 requires replacement, complete the following steps: WARNING! The main power to the Model DF868 must be disconnected before proceeding. 1. Open the cover on the electronics console. For LVD compliant units, remove the two mounting screws and lift the clear plastic shroud out of the electronics console.
Chapter 4. Parts Replacement 4.3 Removing the Printed Circuit Board All of the remaining maintenance procedures discussed in this chapter require removal of the printed circuit board. Refer to Figure 8 on page 35 and Figure 9 on page 36 while completing the following tasks: 1.
Chapter 4. Parts Replacement 4.4 Replacing the EPROM The Model DF868’s User Program is stored on an erasable programmable read only memory (EPROM) chip. The EPROM, which is designated as component , is located in the top left corner of the rear of the printed circuit board. See Figure 9 on page 36 for a rear view of the printed circuit board.
Chapter 4. Parts Replacement 4.5 Installing an Option Card (cont.) J41–J46 3. There are six 32-pin option card sockets ( ) on the rear of the printed circuit board. To install an option card, insert its 32-pin connector into any available option card socket and gently press the card into place. Make sure that the pins in the connector are straight and properly aligned with the socket and that the connector is positioned on the right side of the option card.
Chapter 4. Parts Replacement 4.7 Installing the Printed Circuit Board Whether the printed circuit board was removed for replacement or for one of the other procedures discussed in this chapter, reinstallation of the printed circuit board is the final step in the process. Refer to Figure 8 on page 35 and complete the following steps: CAUTION! During this procedure, be very careful not to damage the vertical components along the top...
Appendix A, Service Record. 4.8 Spare Parts All of the necessary components to upgrade or repair the Model DF868 flowmeter are readily available from GE. As a convenient reference, some of the more common spare parts are listed below in Table 5.
Page 42
Chapter 4. Parts Replacement [no content intended for this page] DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Page 43
Chapter 4: Parts Replacement FRONT VIEW – G N/L2 L1 SIDE VIEW BOTTOM VIEW DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Page 44
Chapter 4: Parts Replacement – N/L2 DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Appendix A. Service Record Appendix A. Service Record A.1 Introduction Whenever any service procedure is performed on the Model DF868 flowmeter, the details of the service should be recorded in this appendix. An accurate service history of the meter can prove very helpful in troubleshooting any future problems.
Page 46
Appendix A. Service Record Table 6: Service Record (cont.) Date Description of Service Performed By DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Appendix A. Service Record A.3 Diagnostic Parameters After a successful initial installation of the Model DF868 and whenever any system malfunction is noticed, the values for the diagnostic parameters should be entered in Table 7 below. Table 7: Diagnostic Parameters Parameter Initial Current...
Page 48
Appendix A. [no content intended for this page] DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Appendix B. Optional Enclosures Appendix B. Optional Enclosures B.1 Introduction The Model DF868 is available in optional enclosure types, each of which has been designed to permit easy on-site upgrades and parts replacement. See the foldout drawings at the end of this appendix for details of the applicable DF868 electronics console assembly.
Appendix B. Optional Enclosures B.3 Rack Mount Fuse Replacement If it has been determined that the fuse in the Model DF868 requires replacement, refer to Figure 10 on page 49 and Figure 11 on page 50, and complete the following steps: 1.
Appendix B. Optional Enclosures B.4 Rack Mount Option Card Installation The Model DF868 flowmeter can accommodate up to six option cards in a manner similar to that used in a PC. The option cards are installed into sockets on the printed circuit board, and they are held in place with a metal bracket. A single metal bracket is used to secure all the installed option cards.
Appendix B. Optional Enclosures B.5 Rack Mount EPROM Replacement The Model DF868’s User Program is stored on an erasable programmable read only memory (EPROM) chip. The EPROM, which is designated as component , is located on the corner of the printed circuit board just behind the keypad on the front panel.
Appendix B. Optional Enclosures B.6 Rack Mount LCD Display Replacement The Model DF868 measurements are displayed on a two-pane LCD graphic display panel. The LCD display normally provides years of dependable service, but it is field-replaceable when necessary. To replace the LCD display, refer to Figure 11 on page 50 and complete the following steps: WARNING! The main power to the Model DF868 must be disconnected before proceeding.
Appendix B. Optional Enclosures B.7 Rack Mount Printed Circuit Board Replacement If troubleshooting procedures have indicated a defective printed circuit board, follow the instructions in this section to replace the defective board with a new one. B.7.1 Circuit Board Removal Refer to Figure 11 on page 50 and complete the following steps: 1.
Appendix B. Optional Enclosures B.7.2 Circuit Board Installation Refer to Figure 11 on page 50 and complete the following steps: 1. Position the new printed circuit board within the electronics console so that it rests on the six standoffs in the base of the enclosure and the option card sockets are located near the rear of the enclosure.
Page 56
Appendix B. [no content intended for this page] DigitalFlow™ Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Page 60
Index S (cont.) Option Card Shroud ....... . 30 ......27 Bracket Aluminum .
Page 61
AUTHORIZATION NUMBER (RAN), and shipping instructions for the return of the instrument to a service center will be provided. 2. If GE Sensing instructs you to send your instrument to a service center, it must be shipped prepaid to the authorized repair station indicated in the shipping instructions.
Page 62
Warranty [no content intended for this page] DigitalFlow™ DF868 Multipurpose Ultrasonic Liquid Flowmeter Service Manual...
Page 63
• Cable glands of an approved flameproof design are required. These must be installed according to the manufacturer’s instructions. Where the cable glands are provided by GE, the manufacturer’s instructions, as supplied, to GE, will be included in the documentation.
Page 65
EC DECLARATION Sensing CONFORMITY DOC-0013, Rev. B GE Sensing 1100 Technology Park Drive Billerica, MA 01821 declare under our sole responsibility that the DigitalFlow™ DF8688 Liquid Ultrasonic Flowmeter DigitalFlow™ GC868 Clamp-On Gas Ultrasonic Flowmeter DigitalFlow™ GF868 Flare Gas Mass Ultrasonic Flowmeter DigitalFlow™...
Page 68
Customer Support Centers U.S.A. The Boston Center 1100 Technology Park Drive Billerica, MA 01821 U.S.A. Tel: 800 833 9438 (toll-free) 978 437 1000 E-mail: sensing@ge.com Ireland Sensing House Shannon Free Zone East Shannon, County Clare Ireland Tel: +353 61 61470200 E-mail: gesensingsnnservices@ge.com An ISO 9001:2008 Certified Company www.gemeasurement.com/en/about-us/quality.html...