Tektronix 422 Instruction Manual Download

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Type 422 AC-DC

SECTION

PERFORMANCE CHECK/CALIBRATION

Change information, if any, affecting this section will be found at the rear of this manual.

Introduction

To assure instrument accuracy, check the calibration o f

the Type 422 every 1000 hours o f operation, or every six

months if used infrequently. Before complete calibration,

thoroughly clean and inspect this instrument as outlined in
the Maintenance section.

As an aid to the calibration of the instrument, a

Short-Form  Procedure  is  given  prior  to  the  complete
procedure.  To  facilitate  instrument  calibration  fo r  the
experienced  calibrator,  the  Short-Form  Procedure  lists  the
calibration  adjustments  necessary  fo r  each  step  and  the
applicable  tolerances.  This  procedure  also  includes the step
number  and  title   as  listed  in  the  complete  Performance
Check/Calibration  Procedure  and  the  page  number  on

which  each  step  begins.  Therefore,  the  Short-Form  Pro
cedure  can  be  used  as  an  index  to  locate  a  step  in  the
complete  procedure.  Another  feature  o f  the  Short-Form

Procedure is the spaces provided to record performance

data  or  to  check  o ff  steps  as  they  are completed.  This  pro
cedure  can  be  reproduced  and  used  as  a  permanent  record
of  instrument calibration.

The complete Performance Check/Calibration Procedure

can  be  used  to  check  instrument  performance  w itho ut
removing  the  covers  or  making  internal  adjustments  by
performing  all  portions  except  the ADJUST- part of a  step.
Screwdriver  adjustments  which  are  accessible  w ithout
removing  the  covers are adjusted  as part of the performance
check  procedure.  A  note  titled  PERFORMANCE  CHECK
ONLY  gives  instructions  which  are  applicable  only  to   the

performance check procedure and if necessary, lists the
next applicable step fo r the performance check procedure.

Completion o f each step in the complete Performance

Check/Calibration  Procedure  insures  that  this  instrument
meets  the  electrical  specifications  given  in  Section  1. Where
possible,  instrument  performance  is  checked  before  an

adjustment is made. For best overall instrument perform
ance when performing a complete calibration procedure,

make each adjustment to the exact setting even if the

CHECK— is w ithin the allowable tolerance.

NOTE

All waveforms shown in this procedure were taken

with a Tektronix Oscilloscope Camera System.

Limits, tolerances and waveforms in this procedure

are given as calibration guides and should not be

interpreted as instrument specifications except as

specified in Section 1.

A partial calibration is often desirable after replacing

components,  or  to  touch  up the adjustment o f a  portion  of
the  instrument  between  major  recalibrations.  To  check  or
adjust  only  part  o f  the  instrument, set the controls as given
under  Preliminary  Control  Settings  and  start  w ith  the
nearest  test  equipment  picture  preceding  the  desired
portion.  If  any  controls  need  to   be  changed  from   the
preliminary  settings  fo r  this  portion  o f  the  calibration
procedure,  they  are  listed  under  the  heading  Partial
Procedure  following  the  equipment  required  picture.  To

prevent unnecessary recalibration o f other parts o f the

instrument, readjust only if the tolerance given in the

CHECK— part of the step is not met. If readjustment is
necessary, also check the calibration o f any steps listed in

the INTERACTION— part o f the step.

TEST EQUIPM ENT R EQ U IR ED

General

The follow ing test equipment and accessories, or its

equivalent,  is  required  fo r complete calibration  o f the Type
422.  Specifications  given  are  the  minimum  necessary  fo r
accurate  calibration.  Therefore,  some  o f  the  recommended
equipment  may  have  specifications  which  exceed  those

given.  A ll  test  equipment  is  assumed  to  be  correctly
calibrated  and  operating  w ithin   the  given  specifications.  If
equipment  is  substituted,  it  must  meet  or  exceed  the
specifications o f the  recommended equipment.

Special Tektronix calibration fixtures are used in this

procedure only where they facilitate calibration. These

special calibration fixtures are available from T ektronix,

Inc. Order by part number through your local T ektronix
Field Office or representative.

Test Equipment

1. Variable DC power supply1. Voltage range, at least

+11 to +35 volts; current capability, at least 2.5 amperes;
output voltage monitored w ithin 3%. For example, Trygon

Model HR40-5B.

2. Precision DC voltm eter1. Accuracy, w ithin 0.1%;

resolution, 50 microvolts; range, zero to 100 volts. For

example, Fluke Model 825A Differential DC Voltm eter.

3. Test oscilloscope. Bandwidth, DC to five megahertz;