HP E5970A User manual

User's Guide
HP E5970A Optical Power Meter
SERIAL NUMBERS
This manual applies to all instruments.
HP Part No. E5970-91011
Printed in the Federal Republic of Germany
First Edition
E0295

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Subject Matter
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- -
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Control Serial Number: Edition 1 applies dir~ctly
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Edition 1
: 1st February 1996 : E6970-91011 : E0296

Safety Summary
The following general safety precautions must be observed during all phases
of operation, service, and repair of this instrument. Failure to comply with
--
these precautions or with specific warnings elsewhere in this manual violates
safety standards of design, manufacture, and intended use of the instrument.
Hewlett-Packard Company assumes no liability for the customer's failure to
comply with these requirements.
General This is a Safety Class 111 instrument and has been manufactured and
tested according to international safety standards.
Operation - Before applying power Comply with the installation section.
Additionally, the following shall be observed:
Do not remove instrument covers when operating.
rn Do not operate the instrument in the presence of flammable gases or fumes.
Operation of any electrical instrument in such an environment constitutes
a
definite safety hazard.
Do not install substitute parts or perform any unauthorized modification to
the instrument.
Be aware that capacitors inside the instrument may still be charged even if
-
the instrument has been disconnected from its source of supply.
Safety Symbols
- A
The apparatus will be marked with this symbol when it is
necessary for the user to refer to the instruction manual to
protect the apparatus against damage.
-
Frame or chassis terminal.
--
Protective conductor terminal.
iii

Warning
The WARNING sign denotes a hazard. It calls attention to
-
a procedure, practice or the like, which, if not correctly
performed or adhered to, could result in injury
or loss of
life. Do not proceed beyond
a WARNING sign until the
indicated conditions are fully understood and met.
-
Caution
The CAUTION sign denotes a hazard. It calls attention to
an operating procedure, practice or the like, which, if not
correctly performed or adhered to, could result in damage to
or destruction of part or all of the equipment. Do not proceed
beyond a CAUTION sign until the indicated conditions are fully
understood and met.
Introduction
This guide has two sections
rn How to operate the instrument (chapters 1 and 2), and
Supporting information, which is not required for the general operation of the
instrument (appendicesA to
F).
-

Contents
Making Measurements
.......... Switching the Power Meter On
Switching the Power Meter On Permanently
...
............. Zeroing the Instrument
......... Switching the Power Meter Off
Configuring the Wavelength
...........
............ Measuring Absolute Power
Holding the Value on
the Display ........
Releasing the Value on the Display ......
Measuring Relative Power ............
Selecting the Relative Power Measurement
...
Holding the Value on the Display .......
Releasing the Value on the Display .....
Measuring a Reference .............
Entering or Editing the Reference .......
Example: Making a Loss and Power Measurement
2 . Identifying Modulated Light
Identifying Fibers in a Cable .................. 2-1
........ Example: Identifying the Modulation Frequency
2-2
A. Preparing for Operation
Initial Inspection ........................ A-l
Power Supply Requirements .................. A- 1
Changing the Batteries .................... A-2
Operating and Storage Environment .............. A-3
Temperature ......................... A-3
Humidity .......................... A-3
Optical Input
......................... A-3
................
Attaching a Connector Adapter A-4
................
Removing a Connector Adapter A-4
................... Connecting Bare Fibers A-5

B . Ordering Information
.........................
Instruments B-1
................
AC Adapter (HP E5974A only) B-1
......................
Connector Adapters B-2
C . Specifications
......................
Definition of Terms C-1
...................
Performance Specifications C-1
...........
Supplementary Performance Characteristics C-3
..................
Typical Spectral Responsivity C-3
.....................
General Specifications C-4
D . Performance Test
....................
Required Test Equipment D- 1
.......................
Performance Test D-2
...........................
General D-2
........................
Linearity Test D-2
........................
Uncertainty Test D-4
..........
PC.The Wavelength-Corrected Power Level D-7
E . Cleaning Procedures
........................
The Cleaning Kit E-1
.....................
Other Cleaning Tools E-2
.....................
Preserving Connectors E-3
.................
Cleaning Instrument Housings E-4
......................
Cleaning Procedures E-4
..................
Cleaning Cable Connectors E-4
.................
Cleaning Connector Adapters E-5
................
Cleaning Connector Interfaces E-5
.................
Cleaning Bare Fiber Adapters E-6
..................
Cleaning Bare Fiber Ends E-6
.............
Cleaning Physical Contact Interfaces E-7
..............
Cleaning Recessed Lens Interfaces E-7

Making Measurements
This chapt,erdescribes the normal operation of the power meter, that is making
power and loss measurements.
-
Switching the Power Meter On
- - -- ~~
Note
Normally the power meter switches off aut~omaticallyafter
a period of
20 minutes. If you need to make measurements
for a longer period, see "Switching the Power Meter On
Permanently".
To switch the power meter on:
1. Press I-).
E5910A OPTICAL POWW METER '
800 - 1800 run
I'
The Power Meter Display at Power On
The whole display, except the bottom right corner, is filled for approximat,ely 2
seconds, then the number ::::::8B is displayed for approximately 2 seconds, after
which the power meter is ready to use.
If the power meter does not switch on, check the battery (see "Changing the
Batteries" in Appendix A for information on accessing,
and changing, the
battery).
Making Measurements 1-1

I1 Switchingthe Power Meter On Permanently
To switch the power meter on permanently:
1. Press and hold [m).
2. Wait until PERM appears in the bottom right corner of the display
(approximately
2 seconds). (The whole display is filled for approximat,ely 2
seibnds while-youhold the button).
E5970A OPTICALWW METER
800 - I800 om
The Power Meter Display at Permanent Power On
3. Release cm).
The number 8888 is displayed for approximately 2 seconds, after which the
power meter is ready to use.
-
If the power meter does not switch on, check the battery (see "Changing the
Batteries" in Appendix A for information on accessing, and changing, the
battery).
Zeroing the Instrument
You do not have to zero the instrument. The instrument zeros itself
approximately
20 seconds after you switch it on, and then approximately every
10 minutes during operation.
While the instrument is zeroing itself,
:38 appears in the lower left hand corner
(where the modulation is shown).
1-2 Making Measurements

The Calibration Indicator
While the instrument is zeroing, any key presses you make are stored, and are
executed when the zero operation is finished.
Switchingthe Power Meter Off
To switch the power meter off:
1. Press (-1.
- Configuring the Wavelength
The wavelength is shown at the bottom of the display in the middle.
There are four calibrated wavelengths that you can choose from:
8 850nm
1300nm
1310nm
1550nm
-
To change the wavelength
1. Press repeatedly until the wavelength you want is shown.
The Sel X Key and the Wavelength Display
Making Measurements 1-3

I1 Power readings are valid for wavelengths within h2nm of the selected
wavelength. If the measurement wavelength is not within these limits, you
can correct the reading using the typical spectral responsivity curve given in
"Typical Spectral Responsivity" in Appendix
C.
If you cannot change the wavelength check the following:
Is
REF shown at the top left of the display?
If it is,
1. press (dB/Refj.
2. Change the wavelength as described above.
Note
You may have changed the value of your reference. See
"Measuring a Reference" and "Entering or Editing the
Reference" for information about taking and editing references.
Is the wavelength shown on the display alternating with
HOL?
If it is,
1. Press m.
2. Change the wavelength as described above.
Measuring Absolute Power
The power measured at the optical input is shown by the large digits on the
display, with the units to the right of the measurement.
There are three units that you can choose from:
dBm, which is one of the units for absolute power measurements,
Watts, which is the other unit for absolute power measurements, and
dB, which is the unit for relative power measurements, and is described in
"Measuring Relative Power".
To select absolute power measurement and the unit:
1. Press CdBm/Wj repeatedly until the unit you want is shown.
1-4 MakingMeasurements

IILJ
The dBm/W Key and the Power Unit
If you cannot change the unit check the following:
rn Is the wavelength shown in the middle at the bottom of the display
alternating with
H!IL?
If it is,
I. Press CHold).
2. Change the unit as described above.
Holding the Value on the Display
The value for the power on the display is updated approximately every half a
-
second. To hold the value,
I. Press (Holdl.
The Hold Key and the Hold Indicator
While the value is being held, the indicator HCiL is shown, alternating with the
wavelength, in the middle at the bottom of the display.
Releasingthe Value on the Display
If a power value is being held on the display, you can release it by pressing IHold)
a second time.
MakingMeasurements 1-5

The power measured at the optical input is shown by the large digits on the
display, with the units to the right of the measurement.
To make relative power measurements, you need to select dB units, and then
measure or edit in the reference against which the relative power is measured.
Selecting the Relative Power Measurement
Altogether there are three units that you can choose from:
rn dBm, which is one of the units for absolute power measurements, and is
described in "Measuring Absolute Power",
Watts, which is the other unit for absolute power measurements, and is
described in "Measuring Absolute Power", and
dB, which is the unit for relative power measurements.
To select the relative power measurement and the unit:
1. Press [j) repeatedly until the units at the right of the display are IJE:.
The dB/Ref Key and the Power Unit
OR
Make a reference measurement (see "Measuring a Reference").
If you cannot change to measuring the relative power, check the following:
Is the wavelength shown in the middle at the bottom of the display
alternating with
HOL?
If it is,
1. Press lHold).
2. Change the unit as described above.
Holding theValue on the Display
The value for the power on the display is updated approximately every half a
second.
To hold the value,
1-6 MakingMeasurements

1. Press m.
While the value is being held, the indicator HCiL is shown, alternating with the
wavelength, in the middle at the bottom of the display.
-
Releasing the Value on the Display. If a power value is being held on the
display, you can release it by pressing
IHold) a second time.
Measuring a Reference
Note
A separate reference is stored for each calibrated wavelength.
Make sure the correct wavelength has been selected before you
measure.
To measure a reference:
1. Connect the power meter to the point at which the reference is to be
measured.
2. Press [-I.
If you cannot measure a reference, check the following
-
Is REF shown at the top left of the display?
If
it is,
1. Press @$KT).
2. Measure the reference as described above.
w Is the wavelength shown in the middle at the bottom of the display
alternating with
HIIIL?
If it is,
1. Press lHold).
2. Measure the reference as described above.
Entering or Editing the Reference
Note
A separate reference is stored for each calibrated wavelength.
Make sure the correct wavelength has been selected before you
edit.
-
To enter or edit a reference value:
1. Press (dB/Ref) repeatedly, until REF is shown at the top left of the display.
Making Measurements 1-7

The dB/Ref Key and the Reference Indicator
2. Edit the value for the reference using the Modify keys
@ increases the value of the flashing digit by one.
rn le=) scrolls the flashing digit to the next digit on the left.
rn decreases the value of the flashing digit by one.
If you cannot enter or edit the reference, check the following
rn Is the wavelength shown in the middle at the bottom of the display
alternating with
HOL?
If it is,
1. Press
@.
2. Measure the reference as described above.
Example: Making a Loss and Power Measurement
This example describes how to measure the power through, and the loss due to
a badly made connection.
In this example, we use
rn The HP E5970A Optical Power Meter with a HP 81005AA HMS-10 Adapter,
A HP E5974A Dual Laser Source with a HP 81005AI HMS-10 Adapter,
rn Two HP 81101AC Diamond HMS-1OMP to HMS-1O/HP Patchcords,
rn HP 81000UM Universal Through Adapter with a HP 81000AI HMS-10 Adapter.
1. Set up the equipment as shown in the diagram:
1-8 MakingMeasurements

Set Up for Power and Loss Measurement Example
a. Switch on both the inst,ruments.
b. Press c=] on the laser source, and make sure CW is lit (press
repeatedly until it is, if necessary).
c. Press on the power meter until 1550nm is selected.
2. Measure the reference:
a. Press
cj).
3. Make the DUT.
-
a. Separate the two connectors in the through adapter (HP 81000UM).
4. Measure the loss:
a. Read the value for the loss in
dB on the display of the power meter.
5. Measuring the power through the connector pair:
a. Press
c-1.
b. Read the value for the power in dBm on the display of the power meter.
c. Press CdBm/W).
d. Read the value for the power in Watt on the display of the power meter.
Making Measurements 1-9

Identifying Modulated Light
This chapter describes how to use the power meter to identify different fibers in
a cable.
Identifying Fibers in a Cable
The HP E5970A Optical Power Meter recognizes signals modulated at 270Hz,
330Hz, IkHz, and 2kHz. The modulating frequency is shown at the bottom left
of the display.
The Modulation Indicator
The modulating frequencies recognized by the power meter are available from
the
HP E5972A and HP E5974A sources, except for the 330Hz modulation. By
connecting one or more sources you can use the power meter to identify fibers
at the far end of the cable.
Note
If you are not making absolute power measurements, for
example where you only need to identify the modulation
frequency, it is not necessary to set the value for the
- wavelength.
If the power meter does not display the modulation, but does display
-- in the
position of the modulation indicator, then the power of the incoming signal
Identifying Modulated Light 2-1

is not high enough for the power meter to identify the modulation. This will
I
happen at power levels below -45dBm at 850nm, and at power levels below
-50dBm at 1300nm, 1310nmand 1550nm.
Example: Identifying the Modulation Frequency
In this example, we will identify on the power meter the modulating frequency
being used
by the source.
The example uses the following equipment:
a The HP E5970A Optical Power Meter with a HP 81005AA HMS-10 Adapter,
rn A HP E5972A LED Source with a HP 81005AA HMS-10 Adapter,
A HP 81101AC Diamond HMS-10MP to HMS-fOMP Patchcord.
1. Set up the equipment as shown in the diagram:
Set Up for Power and Loss Measurement Example
2. Switch on both the instruments.
3. Press on the source. Note that the modulation indicator on the power
meter shows 270Hz (after a slight delay).
4. Press on the source. Note that the modulation indicator on the power
meter shows
]kHz (after a slight delay).
5. Press on the source. Note that the modulation indicator on the power
meter shows
2kHz (after a slight delay).
2-2 Identifying Modulated Light

Preparing for Operation
This section covers the information you need to know to set up your
instrument.
Initial Inspection
Inspect the shipping container for damage. If there is damage to the container
or cushioning, keep them until you have checked the contents of the shipment
for completeness and verified the instrument both mechanically and electrically.
The Appendix
D gives a procedure for checking the operation of the instrument.
If the contents are incomplete, mechanical damage or defect is apparent,
or if an instrument does not pass the operat,or'schecks, notify the nearest
Hewlett-Packard office.
Power Supply Requirements
The instrument is powered by t,wo 1.5V dry batteries (Mignon AA size), for an
operating period of approximately
36 hours, or two 1.2V rechargeable batteries
for an operating period of approximately
12 hours.
When the batteries are low, the low-battery indicator is shown on the display.
At this stage, there is approximately enough charge for another
30 minutes of
use.
Preparing for Operation A-I

p970~ OmlCALPOWWMETER
800 - 1800 nm
The Low-Battery Indicator
Changing the Batteries
To change the batteries,
1. Loosen the thumbscrews on the rear of the instrument.
The Thumbscrews on the Rear of the Instrument.
2. Remove the cover.
Removing the Rear Cover.
3. Remove the batteries.
4. Making sure that the polarity is correct (it is shown on the bottom of the
battery compartment), insert the new batteries.
5. Put the cover back on.
6. Tighten the thumbscrews with your fingers.
A-2 Preparing for Operation