General Check , Adjust Ing And Checking - Philips PM 5167 Instruction Manual

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3.3.
GENERAL CHECK. ADJUSTING AND CHECKING
- The tolerances mentioned in this chapter only apply for a newly adjusted instrument and can deviate from
the values mentioned in chapter 1.2. TECHNICAL DATA.
....
- The instrument only must be adjusted af ter a warming'up of at least 30 minutes at an ambient temperature
of +(23±3) °C.
- The adjustment of Frequency Switch Unit U2 and Controi Unit U5 mu st be performed with completely
closed instrument; if necessary. the instrument must be newly warmed-up after an adjusting procedure.
The remaining units must possibly be performed with el osed instrument; in no case, use an extension p.w.b.
- If not indicated differently :
- the voltages, given in this chapter, are measured with respect to the signal earth ( -=1=- )
- The following abbreviations are used for the various measuring instruments :
L
=
open
Q
=
oscilloscope with an input impedance of 50 Q *
e .g. PHILIPS PM 3250
Z
=
counter e.g. PH ILI PS PM 6620
V
=
digital voltmeter (d.c. ) e.g. PH ILI PS PM 2441
AC·V
=
AC·milivoltmeter
e.g. PHI LIPS PM 24548
K
=
distorsiometer
e.g. Hewlett Packard, type 334A
­
G
=
generator e.g. PHILIPS PM 5126
50Q
=
load resistor 50
Q,
3 W
e.g. PHILIPS PM 9581
1 nF
=
capacitor 1 nF
*
Measuring cable terminated with 50
Q
at the side of the oscilloscope.
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