Measurement System Calibration Verification Procedure

1
Measurement System Calibration Verification
Procedure

Copeland Corporation Sound and Vibration
Laboratories
2
Calibration Verification Procedure

• 2133 analyzer digital and analog self tests
• Verify calibration of sound measurement set up
• Measure and record the P/I index
• Verify the calibration of the start/stop
  measurement set up
• Perform intensity sweep of reference fan
• Vibration mastering procedure

3
Assemble equipment and documentation materials

• 2133 analyzer
• BZ511Z floppy disk
• Mysetups floppy disk
• Two BNC cables with connections
• Pistonphone kit
• Centigrade thermometer
• Digital tachometer
• Reference fan

4
Assemble equipment and documentation materials

• Correct R file
• With calibration/verification log sheet
• Correct dat file floppy disk
• Correct P/I index floppy disk
• Correct reference fan control chart

5
Step One

• Powering up, and the Digital and Analog Self
  Tests.

6
With the power to the 2133 analyzer off...

• Press the POWER key. The analyzer will
  automatically perform and display the results of
  the digital self test.

7
After the Digital Self Test has completed
itself...

• Record the results on the calibration
  verification log sheet.(space 6)
• The analyzer initialization screen will appear.

8
From the analyzer initialization screen...

• Insert the BZ511Z floppy disk into the 2133.
• Press the R/S key. After a short delay, the
  analog self test screen will be displayed.

9

• Using the BNC cables, connect the signal
  generator port, to both of the direct input ports
  on the 2133. Ports are located underneath of the
  keyboard.

10

• Make sure that both of the polarity voltage
  switches for channels A and B are set to 200v.
  (switches in top position)
• Make sure that all three ground switches are to
  the right.
• Press the R/S key again.

11

• The analyzer should automatically begin to
  perform the first of the six trials that make up
  the analog self test. This test lasts
  approximately four minutes.

12
After the analog self test completes itself...

• Date will appear in the top right corner of the
  2133 screen
• Note If all of the six individual segments of
  the analog self test are not passed, recheck all
  of the connections and switches described in the
  preceding steps, and restart the analog self
  test.

13
To restart the analog self test...

• Press the RESET and keys simultaneously.
  This will bring you back to the analyzer
  initialization screen. Proceed to the analog self
  test screen as before by .
• Pressing the R/S key Once the analog self test
  screen appears
• Press the R/S key again to restart the test.

14
IMPORTANT !!!

• If after repeating the analog self test, all of
  the segments of the test are not passed, notify
  the lab manager before proceeding.

15

• Finally, document the results of the analog self
  test on the calibration verification log
  sheet,(space 7) with a P or an F.

16
After the analog self test is completed...

• Press the R/S key again

17
At this time...

• Remove the BNC cables from the signal generator
  and direct inputs
• Eject the BZ5117 floppy disk

18
Step Two

• RECALL MYSETUPS

19
Recall Mysetups

• Insert the Mysetups floppy disk into the
  analyzer
• Press the LIST key to view the contents of the
  disk

20
Recall Mysetups

• Using the arrow keys on the keypad of the
  analyzer, move the cursor to highlight the word
  MYSETUPS on the analyzer screen
• Press the RECALL key
• Press the EXECUTE key

21
STEP 3

• Verify the Calibration of the Sound Measurement
  Set up

22
Select set up number 3.(If it is not already
displayed)

• Using the arrow keys, move the cursor to
  highlight the number in the top left corner of
  the analyzer screen
• TIP Pressing the display key will quickly move
  the cursor to the top left corner of screen
• Press the 3 key
• Press the ENTER key

23
Select set up number 3.(If it is not already
displayed)

• Again using the arrow keys, move the cursor to
  highlight the number on the left center of the
  analyzer screen
• Press the 3 key
• Press the ENTER key

24
Select the correct cursor setting.(If it is not
already displayed)

• Using the arrow keys, highlight the word in the
  top right corner of the analyzer screen
• Using the field entry keys, or scroll in
  one direction until the word Main is displayed

25
Select the correct cursor setting.(If it is not
already displayed)

• Using the arrow keys, move the cursor down one
  position
• Using the field entry keys, scroll through until
  the letters, Avg.T are displayed

26
Enter the correct microphone sensitivities (If
they are not already displayed)

• Check the current, Calibration Log Sheet for
  Sound Power Measurement Set up to verify the
  correct set up number, and microphone
  sensitivities for channels A and B.

27
Enter correct microphone sensitivities

• Using the arrow keys, move the cursor to
  highlight the microphone sensitivity setting for
  channel A
• Using the number keys, type the correct
  microphone sensitivity for the microphone in
  channel A.
• NOTE Dont forget to include the lower case m
  after the last digit of the sensitivity value
• Press the ENTER key.

28
Enter correct microphone sensitivities

• Using the arrow keys, move the cursor to
  highlight the microphone sensitivity setting for
  channel B.
• Using the number keys, type the correct
  microphone sensitivity for the microphone in
  channel B.
• NOTE Dont forget to include the lower case m
  after the last digit of the sensitivity value
• Press the ENTER key.

29
Measure and record current ambient pressure and
temperature

• With a centigrade thermometer, measure the
  current ambient temperature inside of the sound
  test room.
• Record this temperature in the proper space on
  the Calibration/Verification Log Sheet (10)

30
Measure and record current ambient pressure and
temperature

• Using the barometer include in the calibration
  kit, measure the current ambient pressure inside
  of the sound room. Take the pressure reading (in
  mb)from inside scale on the barometer face.
• Interpolate marks on scale to read the largest
  whole number. (example reading)
• Record the pressure reading in the correct space
  on the Calibration/Verification Log Sheet

31
Measure and record current ambient pressure and
temperature

• Using the barometer again, find the ambient
  pressure correction value by reading the outside
  scale on the barometer face.
• Record this value in the correct space on the
  Calibration Verification Log Sheet (9).

32
About the ambient pressure correction...

• Use this correction with the calibration
  pressures in space numbers 15,19,29 of the
  calibration/verification log sheet to determine
  the corrected calibration pressures in space
  numbers 16,20,30
• Pay close attention to the positive and negative
  numbers on barometer scale, and when adding the
  correction to the microphone calibration
  pressures.

33
Enter current ambient temperature and pressure
into analyzer

• Press the SYSTEM SETUPS key
• Using the arrow keys, move the cursor to
  highlight the ambient pressure setting on screen
• Using the number keys, enter the current ambient
  pressure, as measured in the previous steps.
• Press the ENTER key.

34
Enter current ambient temperature and pressure
into analyzer

• Using the arrow keys, move the cursor to
  highlight the ambient temperature setting on
  screen
• Using the number keys, enter the current ambient
  temperature, as measured in the previous steps.
• Press the ENTER key.
• Press the GRAPH FORMAT key to return to
  original measurement screen.

35
Connect probe microphones, pistonphone , and
base assembly

• NOTE It is recommended to work at floor level
  when performing the following steps, so that any
  of the delicate components wont have far to fall
  in case the might be accidentally dropped.

36
Connect probe microphones, pistonphone , and
base assembly

• Remove the flat disk that is stored underneath
  the barometer in the calibration kit.
• Screw this disk onto the pistonphone base, also
  found in calibration kit, in a clockwise
  direction.

37
Connect probe microphones, pistonphone , and
base assembly

• Remove the foam windscreen from the head of the
  intensity probe.
• Locate the small silver lever, where the probe
  handle meets the head assembly.
• Gently turn the lever counterclockwise to loosen
  and remove the head assembly from the probe
  handle.

38
Connect probe microphones, pistonphone , and
base assembly

• Loosen one of the small black knobs on the head
  assembly by gently turning it counterclockwise.
• Gently slide one of the microphones back, or away
  from the spacer.
• Unscrew, and remove spacer from the microphone it
  is still in contact with by gently turning spacer
  counterclockwise.

39
Connect probe microphones, pistonphone , and
base assembly

• Insert both of the microphones into the top ports
  on opposite sides of the base assembly.
• Gently but firmly, push both of the microphones
  as far into the base as it will go.

40
Connect probe microphones, pistonphone , and
base assembly

• Remove the pistonphone from the calibration kit,
  turn it upside down, and insert it on top of the
  base assembly.
• Slide the POWER switch on the body of the
  pistonphone to the ON position.

41
About the pistonphone...

• Anytime that the pistonphone switch is in the
  ON position, the 250Hz light on the side
  pistonphone body should be illuminated.
• If light flickers, or does not come on at all,
  unscrew pistonphone body and install six fresh
  AA batteries.

42
Verify the calibration of the sound measurement
system

• Press the START key on the analyzer.
• Watch as the averaging time counts to fifteen
  seconds and stops.(In upper right of screen)
• Read the measured calibration pressure for
  channel A in the top right of the analyzer screen
  next to the letter y.

43
Verify the calibration of the sound measurement
system

• Record the measured calibration pressure for
  channel A in the appropriate space on the
  calibration/verification log sheet.(17)
• Subtract this number from the previously
  calculated corrected calibration pressure in the
  space above.(16)
• Record the difference in the space below.(18)

44
Important !

• When verifying the calibration of any microphone,
  the difference between corrected calibration
  pressure, and the measured calibration pressure
  should not exceed .3 dB.
• If the measured value does not fall within these
  parameters, check all switches and connections,
  and retest by pressing the START key again.
• I f difference still exceeds .3 dB note the
  difficulty on log sheet, and notify the
  laboratory manager ASAP.

45
Verify the calibration of the sound measurement
system

• Using the arrow keys, highlight the area on the
  top left corner of the analyzer screen that
  reads.Chan.A
• Press either of the FIELD ENTRY keys one time.
• Chan.B should now appear in the highlighted
  portion of the screen.

46
Verify the calibration of the sound measurement
system

• Read the measured calibration pressure for
  channel B on the top right side of the analyzer
  screen next to the letter y.
• NOTE It is not necessary to press the start key
  again to measure channel B, both channels are
  measured at the same time, the analyzer screen
  only displays one channel at a time.

47
Verify the calibration of the sound measurement
system

• Record the measured calibration pressure for
  channel B in the appropriate space (21) on the
  calibration/verification log sheet.
• Subtract this value from the previously
  calculated corrected calibration pressure in the
  space above. (20)
• Record the difference in the space below. (22)

48
Verify the calibration of the sound measurement
system

• Follow the procedure described in the previous
  steps if the difference between the corrected
  calibration pressure and the measured calibration
  pressure exceeds .3 dB.
• Remove the pistonphone from the head assembly.
• Slide the pistonphone POWER switch to the OFF
  position.

49
STEP 4

• Measure the P/I index

50
Measure the P/I index

• Remove the reference sound source from the
  calibration kit, turn it upside down, and attach
  it to the base assembly in the same manner as the
  pistonphone.
• Press the small black button on the side of its
  body to turn the power on. (the small red light
  should illuminate)

51
Measure the P/I index

• Using the arrow keys, move the cursor to
  highlight the number in the top left corner of
  the analyzer screen.
• Press the number 4 key.
• Press the ENTER key.

52
Measure the P/I index

• Again using the arrow keys, move the cursor to
  highlight the number in the center of the left
  side of the analyzer screen.
• Press the number 4 key.
• Press the ENTER key.

53
Measure the P/I index

• Press the INPUT AUTORANGE key.
• NOTE After pressing the autorange key, wait a
  few seconds until any, or all of the following
  messages appear then disappear from the bottom of
  the analyzer screen.(2 to 3 seconds)
• waiting for settling of inputs
• input autorange in progress
• attenuator verification

54
Measure the P/I index

• Press the START key.
• The P/I index measurement will begin, and last
  for two minutes.
• You may observe the time advance at the top right
  of analyzer screen next to Avg...T

55
Measure the P/I index

• At the conclusion of the two minute measurement,
  be sure to turn off the power button on the
  reference sound source.

56
Store the results of the P/I index.

• Remove the MYSETUPS floppy disk from the 2133.
• Insert the P/I index floppy disk that is
  designated for that particular sound room into
  the 2133.

57
Store the results of the P/I index.

• Press the STORE key.
• Using the number keys, type the file name and
  test number, excluding the year.
• NOTE The ALPHA key must be pressed before
  typing a letters on the 2133.

58
Store the results of the P/I index.

• After the test number has been typed, press the
  ENTER key.
• Press the EXECUTE key.
• Storage of the data is complete when the light
  next to the disk drive goes out. (about one or
  two seconds)
• The P/I index floppy disk may be removed from the
  2133 at this time

59
Record the results of the P/I index.

• Press the TABLE key.
• A list of all the frequency bands should appear
  with a P/I value next to them.
• Compare the measured values for each band with
  the original calibration values recorded on the
  Calibration Log Sheet for Reference Sound
  Source, which should be kept in that rooms R
  file.

60
Record the results of the P/I index.