ETS-Lindgren HI-2790B Calibration Comparison System - Manual (Page 8)

8 Introduction www.ets-lindgren.com
 An HI-1710 Microwave Survey Meter to serve as a Local Calibration
Reference (HI-1710 LCR).
Note: For maximum accuracy and traceability, the HI-1710 LCR
and the HI-2623 Probe/Preamp Assembly must be used together
as a single unit. The HI-2623 assembly should not be used for
general oven leakage testing or any other purpose.
The HI-1710 LCR and the HI-2790B Power/Control Module are mounted on top
of the cabinet toward the rear edge. The Power/Control Module is connected
directly to the waveguide through a coax cable assembly. The waveguide
penetrates the chamber and terminates in a slot antenna radiating toward the
probe holding fixture. The fixture is mounted in the wall directly opposite the slot
antenna.
The probe holding fixture is slotted so that the probe can be inserted into the
chamber without removing the probe spacer cone. The fixture allows the probe
under test to be rotated 360 degrees, but has adequate friction to limit axial
motion. A fixture mounted on a horizontal cross-member in the chamber
accurately maintains the spacing of the probe sensing head to the slot antenna.
HI-2790B C ALIBRATION C OMPARISON S YSTEM B LOCK D IAGRAM