Fluke service manual The Components of the 5700A/5720A Series II Calibrator, Service Centers

5700A/5720A Series II Calibrator

Service Manual

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 this manual contains the wideband gain calibration procedure.

1-14. 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 www.fluke.com for locations and phone numbers of authorized Fluke service centers.

1-15. 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.

Apatented 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.

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