Table of Contents
Advertisement
Introduction
This chapter provides the performance test and the calibration adjustment procedures
necessary to verify and maintain the performance of the Instrument over time.
In many of the procedures in this chapter of the manual, the Instrument is
commonly referred to as the UUT (Unit Under Test).
The performance test is a series of tests based on the published 1-year specifications for
the Instrument. It is recommended as an acceptance test when the Instrument is first
received and later as a calibration procedure to ensure that the Instrument meets its
published specifications. Fluke recommends a 1-year calibration cycle for the Instrument.
Calibration adjustments are for correcting out-of-tolerance parameters so they meet
published specifications. If the Instrument fails the performance test, it is an indication
that the Instrument requires calibration adjustment and/or repair. While calibration
adjustment can be accomplished without removal of the covers, repair requires access to
the interior of the Instrument. See Chapter 7, Maintenance, for internal access and repair
information.
The instrument top cover is removable for air filter cleaning access without
the need to break calibration integrity seals. A calibration integrity seal is
located on the internal top shield, revealed once the outer top cover has
been removed (see Chapter 7, Maintenance for details). Additional
calibration integrity seals are located on the rear panel over the lower
outer cover and over the calibration enable switch. It is recommended that
users apply calibration integrity seals in the same three locations.
Environmental and warm up conditions required for the performance test and calibration
adjustments are stated at the beginning of each of the respective sections.
Unless otherwise directed, all connections are made via a Leveling Head of the specified
impedance.
The Leveling Head is an integral part of the UUT functionality.
Recommended Tools and Equipment
A list of the tools and equipment required to verify and maintain the performance of the
Instrument is shown in Table 5-1. If the recommended model is not available, use another
model/brand with the same or better specifications.
The power meters and associated power sensors listed in Table 5-1 automatically apply
corrections for the sensor frequency response, linearity, and temperature. However, in
order to achieve best uncertainties it is common practice to use these devices with
additional calibration factor correction figures obtained by calibration at a primary
laboratory or a national metrology institute, usually measured at a single power level. The
diode sensor designs include compensation for inherent non-linearity of the diode
amplitude response, but at certain test points these "built-in" corrections alone are not
sufficient to achieve the required measurement uncertainty. In addition to the usual
frequency response (or "flatness") calibration factors, corrections must be applied for a
frequency dependent linearity characteristic. These could be determined at the time of
frequency response calibration, or determined separately by comparison with an
inherently linear device such as a thermal power sensor.
Note
Note
Note
Calibration
5
Introduction
5-3
Advertisement
Table of Contents
