FLUKE 5720a___gseng0200 电路图.pdf

5700A/5720A Series II Multi-Function Calibrator Getting Started PN 1668111 March 2002 Rev. 2, 10/07 2002-2007 Fluke Corporation, All rights reserved. Printed in USA All product names are trademarks of their respective companies. RadioFans.CN 收音机爱 好者资料库 LIMITED WARRANTY the display shows linearity, offset, and scale errors Keys that multiply and divide the output value by 10 to simplify work on meters with calibration points at decade multiples of a fraction of full-scale Programmable entry limits used for restricting the levels that can be keyed into the calibrator, preventing access to levels that may be harmful to equipment or personnel A s key that provides the capability of displaying the instruments specification at the selected operating point, calibration interval, and specification confidence level 5700A/5720A Series II Getting Started 2 An auxiliary current binding post that allows you to calibrate meters with separate current inputs without moving cables Real-time clock and calendar for date stamping reports Offset and scaling modes that simplify linearity testing of multimeters Variable phase reference signal output and phase-lock input Interface for the Fluke 5725A Amplifier Standard IEEE-488 (GPIB) interface, complying with ANSI/IEEE Standards 488.1-1987 and 488.2-1987 Selectable normal remote mode or emulation of the Fluke 5100B and 5200A Series calibrators in functions and response to system controller software EIA Standard RS-232C serial data interface for printing, displaying, or transferring internally-stored calibration constants, and for remote control of the calibrator Extensive internal self-testing and diagnostics of analog and digital functions A traceable calibration procedure for all modes and ranges that requires only 10 V, 1 , and 10 k external standards, with only occasional independent verification Fast, simple, automated calibration check providing added confidence between calibration recalls, and data that can be used to document and characterize the calibrators performance between calibration recalls Instruction Manuals The 5700A/5720A Series II Calibrators ship with a complete manual set that contains information for the operator and service or maintenance technicians. The set includes: 5700A/5720A Series II Getting Started Manual (PN 1668111) 5700A/5720A Series II Operator Reference Guide (PN 601648) 5700A/5720A Series II Remote Programming Reference Guide (PN 601655) 5700A/5720A Series II Operator Manual (provided on CD-ROM, PN 1668127, or a printed copy is available for purchase through the Fluke Service Department under PN 601622) 5700A/5720A Series II Service Manual (provided on CD-ROM, PN 1668127, or a printed copy is available for purchase through the Fluke Service Department under PN 105798) Order additional copies of these instruction manuals separately using the part numbers provided. For ordering instructions, refer to the Fluke Catalog or contact a Fluke sales representative. Getting Started Wideband AC Voltage Module (Option 5700A-03) 3 Wideband AC Voltage Module (Option 5700A-03) The Wideband AC Voltage Module (Option 5700A-03) can be installed in both the 5700A and 5720A Series II Calibrators. The module is a high-accuracy, low-noise, extremely flat ac voltage source for calibrating rf voltmeters, with a frequency range of 10 Hz to 30 MHz. Output is in seven ranges from 300 V (-57 dBm) to 3.5 V (+24 dBm) through a Type-N coaxial connector into a 50 load. The output level is selected in volts or dBm through either the front panel controls or under remote control. The wideband module also functions with the calibrators output adjust controls that let display the error of a wideband meter in either percentage of output or in decibels. Included with the wideband module is a Type-N output cable and a 50 terminator. The wideband module is calibrated to the end of its standard-equipment output cable. Auxiliary Amplifier The Fluke Model 5725A Amplifier is available to extend the high voltage performance and current range of the calibrator: Interface connectors on the calibrators rear panel accept cables to directly operate a 5725A. Three amplifiers can be connected to the calibrator at the same time, but only one output can be active at a time. Once you have connected the amplifiers and configured the calibrator in a setup menu, amplifier operation is controlled by the calibrator. Operating instructions for the 5725A are provided in Chapter 4 of the Operators Manual. The General Specifications include specifications for operating the calibrator with the 5725A. For other amplifier specifications, refer to their instruction manuals. Table 1 summarizes the extended capabilities offered by the 5725A. Brief descriptions of the extended capabilities follow. Table 1. Auxiliary Amplifier Data Model Mode Range 5725A Amplifier AC V 20 to 1100 V rms up to 70 mA, 40 Hz to 30 kHz (50 mA < 5 kHz) 220 to 750 V rms up to 70 mA, 30 kHz to 100 kHz DC Amps 0 to 11 A DC Amps 1 to 11 A rms, 40 Hz to 10 kHz 5725A Amplifier The Fluke 5725A Amplifier is an external unit operating under calibrator control to extend ac voltage drive capabilities and both ac and dc current output range. The amplifier adds the following capabilities to the calibrators 1100 V AC range with no compromise in accuracy: Frequency limits at higher voltage increase to 100 kHz at 750 V, 30 kHz at 1100 V. Load limit increases to 70 mA for frequencies above 5 kHz. Capacitive drive increases to 1000 pF, subject to the maximum output current. Extended-performance voltage is available at the calibrators front or rear binding posts, eliminating the need to change cables during a procedure. 5700A/5720A Series II Getting Started 4 A separate set of binding posts on the front panel of the 5725A supplies extended-range ac and dc current outputs. Since most meters have a separate input terminal for the high current ranges, this eliminates the need to change cables during a procedure. The 5725A can also be configured to source all current (both standard calibrator-generated current and its own current) through the 5725A binding posts. Support Equipment and Services Fluke supports your calibration needs with precision, high-quality equipment and a wide range of services. Depending on your needs, location, and capabilities, you may decide to support your 5700A/5720A Series II Calibrator independently or use Fluke services for part, or all, of your support needs. The following paragraphs describe the support equipment and services offered by Fluke for the calibrator. For specifications and ordering instructions for this support equipment and other Fluke instruments, refer to the Fluke catalog, or contact a representative at a Fluke Sales and Service Center. 732B Direct Voltage Reference Standard The Fluke 732B is a rugged, easily transported solid state direct voltage reference standard with a highly predictable 10 V output. This predictability allows the Fluke Standards Laboratory, as well as many Fluke customers, to completely eliminate fragile, saturated standard cells. Laboratories still maintain standard cells using the 732A and 732B as a transportable voltage standard, eliminating the need to transport their standard cells. The 732B can be short-circuited, even for extended periods of time, without damage or loss of stability. It maintains full specified stability over a temperature span of 18 to 28 C. The calibrator uses a 10 V reference standard such as the Fluke 732B in its semi- automated calibration procedure to establish external voltage traceability. Chapter 7 of the Operators Manual describes this procedure. 732B-200 Direct Volt Maintenance Program (U.S.A. Only) The Fluke 732B-200 Direct Volt Maintenance Program provides your laboratory with NIST-traceable 10 V calibration uncertainty as low as 0.6 parts per million. The program maintains the 732B that you keep in your laboratory. To accomplish this, the following occurs: 1. Fluke sends you a calibrated Fluke-owned 732B standard, together with all- necessary connecting cables and instructions for comparison with your 10 V reference standard. 2. You take a series of readings over a five-day period, and return the results to the Fluke Standards Laboratory. 3. The Fluke Standards Laboratory assigns a value to your 10 V standard relative to the NIST legal volt and sends you a report of calibration. 742A Series Resistance Standards The calibrator uses 1 and 10 k resistor standards such as the 742A Series in its semi-automated calibration procedure to establish external traceability of resistance and current. Chapter 7 of the Operators Manual describes this procedure. The 742A Resistance Standards, which are constructed of arrays of Fluke wirewound precision resistors, are ideally suited as support standards for the calibrator. Stability of the resistance transfer standards and their temperature coefficients make them ideal for easy transport to and operation in the calibrators working environment. Getting Started Support Equipment and Services 5 Wideband AC Module (Option 5700A-03) Calibration Support The Wideband AC Module (Option 5700A-03) requires two kinds of calibration: gain and flatness. Gain constants are checked and recalibrated as a part of the normal calibrator semi-automated calibration process. Since frequency flatness is determined by such stable parameters as circuit geometry and dielectric constants, flatness of the Wideband AC module has excellent long-term stability. This stability gives the Wideband AC Module a two-year calibration cycle for flatness calibration. Flatness calibration is required only infrequently, and can be done when the calibrator is returned to a standards laboratory for periodic verification. The 5700A/5720A Series II Service Manual contains the wideband flatness calibration procedure. Chapter 7 of the Operators Manual contains the wideband gain calibration procedure. Service Centers A worldwide network of Fluke service centers supports Fluke instruments and assists customers in many ways. Most service centers have standards and calibration laboratories certified by local national standards organizations. The following is a partial list of the services provided by most service centers: Repair and certified traceable calibration of all Fluke products. Certified traceable calibration of many non-Fluke standards and calibrators. Worldwide exchange of calibrator internal modules. Delivery inside the U.S.A. is typically within 48 hours. Service agreements with the flexibility to suit your needs. These can be a simple warranty extension or an agreement that includes on-site support. Calibration service agreements are also available in many areas. Training programs and seminars, including laboratory metrology, system applications, and product maintenance. Application help and consulting, including system design, hardware selection, custom software, site evaluation and installation. Replacement parts inventory, including recommended spare parts and module kits. Visit for locations and phone numbers of authorized Fluke service centers. 5700A/5720A Series II Getting Started 6 The Components of the 5700A/5720A Series II Calibrator The calibrator is configured internally as an automated calibration system, with process controls and consistent procedures. Internal microprocessors control all functions and monitor performance, using a switching matrix to route signals between modules. Complete automatic internal diagnostics, both analog and digital, confirm operational integrity. Reference amplifiers maintain dc accuracy and stability. Of all technologies available, reference amplifiers have the lowest noise and best stability. Reference amplifiers in the calibrator go through special selection processes including long-term aging to ensure high reliability and performance well within specifications. The calibrator achieves its exceptional ac voltage accuracy by using a patented Fluke rms sensor to make real-time AC/DC comparison measurements. The Fluke rms sensor is similar in principle to the traditional thermal voltage converter, but has a shorter time constant, virtually no reversal error, higher signal-to-noise ratio, and better frequency response. In the calibrator, one Fluke rms sensor serves as an AC/DC transfer standard to develop gain and flatness correction constants during calibration. The second Fluke rms sensor continuously monitors and corrects output voltage during operation. A patented 26-bit digital-to-analog converter (dac) provides the calibrator with the ability to precisely vary its output. This is a pulse-width-modulated dac with linearity typically better than 0.2 ppm of full scale. As with the other internal functions, the linearity of the dac is automatically checked during calibration and analog diagnostics. Calibrating the 5700A/5720A Series II Calibrator The traditional practice of returning a calibrator to a standards laboratory at regular intervals for a full calibration is time consuming, expensive, and disruptive to the task to which the calibrator is being applied. Moreover, it leaves gaps in confidence. You must rely on manufacturers specifications to determine if a calibrator will perform acceptably in an operating environment outside the lab. Also, you must assume that drift is predictable enough so that performance is within limits between recalls. The 5700A/5720A Series II Calibrator makes use of Fluke design breakthroughs in the use of internal check standards and measurement systems. As a result, it can be completely calibrated in place to full specifications using a small number of convenient, portable, environmentally tolerant standards available from Fluke. As you will see below, this procedure is traceable to military standard requirements. When manufactured, each calibrator is calibrated and thoroughly verified with process metrology and calibration standards traceable to the U.S. National Bureau of Standards. A certificate of calibration is included. A calibration verification procedure described in the 5700A/5720A Series II Service Manual is recommended every two years or as required by your established policies. This procedure involves no adjustments. It simply ensures internal processes are in control, and establishes parallel external traceability paths for internal functions such as ac transfers that are never adjusted or corrected. Figure 1 illustrates the time and money that can be saved by using the 5700A/5720A Series II calibration support plan recommended by Fluke. Depending on your policies, you may initially decide to perform calibration verification more often. The calibrator makes this unnecessary and offers you a practical way to collect data unavailable with a traditional calibrator design about performance between calibrations. Getting Started Cali