Newport 835 User manual

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Model835
LaserPico-WattDigitalPowerMeter
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Warranty
Newport Corporation warrants this product to be free from defects in
material and workmanship for a period of 1 year from date of shipment. If
found to be defective during the warranty period, the product will either be
repaired or replaced at Newport’s option.
To exercise this warranty, write or call your local Newport office or
representative, or contact Newport headquarters in Irvine, California. You
will be given prompt assistance and return instructions. Send the
instrument, transportation prepaid, to the indicated service facility.
Repairs will be made and the instrument returned, transportation prepaid.
Repaired products are warranted for the balance of the original warranty
period, or at least 90 days.
Limitation of Warranty
This warranty does not apply to defects resulting from modification or
misuse of any product or part. This warranty also does not apply to fuses,
batteries, or damage from battery leakage.
This warranty is in lieu of all other warranties, expressed or implied,
including any implied warranty of merchantability or fitness for a particular
use. Newport Corporation shall not be liable for any indirect, special, or
consequential damages.
©1987, Newport Corporation
Irvine, California U.S.A.
First Printing (April 15, 1987)
Copyrighted by Newport Corporation, Irvine, CA. All rights reserved. No
part of this manual may be reproduced or copied without the prior written
approval of Newport Corporation.
This manual has been provided for information only and product
specifications are subject to change without notice. Any changes will be
reflected in future printings.
P/N 13767-01, Rev. F3
IN-01872 (7-94)
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About This Manual
This owner’s manual contains all of the necessary information for the
proper operation and maintenance of the Newport Corporation 835 Laser
Pico-Watt Digital Power Meter.
The manual has been divided into the following sections:
Section 1 provides general information about this instrument
Section 2 discusses the operation of the Model 835
Section 3 explains performance verification procedures
Section 4 discusses the Therory of Operation of the Model 835
Section 5 suggests maintenance procedures
Section 6 describes service suggestions and procedures.
See Section 1.1 for an expanded description of these topics and related
references.
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Table of Contents
Warranty................................................................................................................. ii
About This Manual ............................................................................................... iii
List of Illustrations .............................................................................................. vii
List of Tables........................................................................................................ vii
Safety Precautions............................................................................................... vii
Features ............................................................................................................... viii
Specifications ........................................................................................................ ix
Section 1 - General Information
1.1 Introduction..................................................................................................1
1.2 Getting Started .............................................................................................1
1.3 Unpacking and Inspection ..........................................................................3
1.4 Specifications ...............................................................................................3
1.5 Warranty Information ................................................................................. 3
1.6 Manual Addenda ..........................................................................................3
1.7 Safety Symbols and Terms .........................................................................4
1.8 Optional Accessories and Services .......................................................... 4
Section 2 - Operation
2.1 Introduction..................................................................................................5
2.2 Preparation for Use .................................................................................... 5
2.2.1 Line Power............................................................................................5
2.2.2 Battery Pack Power .............................................................................6
2.2.3 Battery Charging ................................................................................ 6
2.3 Tilt Stand ...................................................................................................... 6
2.4 Model 835 Familiarization ...........................................................................7
2.4.1 Digital Display ......................................................................................7
2.4.2 Bar Display ...........................................................................................8
2.4.3 Front Panel Controls ...........................................................................8
2.4.4 Input Connector ................................................................................. 9
2.4.5 Analog Output Connectors ................................................................9
2.5 Error Messages.............................................................................................9
2.6 Environmental Conditions ........................................................................10
2.7 Basic Measurements................................................................................. 10
2.7.1 Power-Up ............................................................................................11
2.7.2 Zero Check .........................................................................................11
2.7.3 Setting Wavelength ...........................................................................12
2.7.4 Setting Attenuator Status .................................................................13
2.7.5 Power Measurements .......................................................................13
2.7.6 Time Constant .................................................................................. 13
2.7.7 Null (REL) Measurements ................................................................13
2.7.8 Ratio Measurements .........................................................................14
2.7.9 Logarithmic Modes (dBm and dB) ..................................................15
2.7.10 Bar Display Zoom and Offset .......................................................... 17
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2.7.11 Storing the Wavelength and Attenuator Status for Power-Up .....18
2.7.12 Inverting Analog Output ...................................................................18
2.7.13 IEEE Interface Option ........................................................................19
2.8 Measurement Considerations ..................................................................19
2.8.1 Detector Calibration and Accuracy ................................................19
2.8.2 Temperature Effects .........................................................................20
2.8.3 Ambient and Stray Light...................................................................20
2.8.4 Wavelength Response of Detector and Attenuator ......................21
2.8.5 Detector Uniformity ..........................................................................22
2.8.6 Detector Saturation...........................................................................22
2.8.7 Attenuator Characteristics ............................................................. 23
2.8.8 Reflections and Interference Effects ...............................................23
2.8.9 Grounding Considerations .............................................................. 23
2.8.10 Changing Detectors...........................................................................23
Section 3 - Perfomance Verification
3.1 Introduction................................................................................................24
3.2 Environmental Conditions ........................................................................24
3.3 Recommended Test Equipment .............................................................. 24
3.4 Initial Conditions ........................................................................................25
3.5 Verification Procedure ............................................................................. 25
Section 4 - Theory of Operation
4.1 Introduction................................................................................................27
4.2 Overall Functional Description ................................................................27
4.3 Photodetector ............................................................................................27
4.4 Electronic Display Functional Description .............................................27
4.4.1 Input Amplifier.................................................................................. 28
4.4.2 Microcomputer and PROM ............................................................. 28
4.4.3 Power Supply .................................................................................... 28
4.4.4 Model 835-BAT Rechargeable Battery Option ...............................28
Section 5 - Maintenance
5.1 Introduction................................................................................................29
5.2 Top Cover Removal/Installation ............................................................. 29
5.3 Battery Pack (Model 835-BAT) Installation ............................................29
5.4 Special Handling of Static Sensitive Devices ......................................... 30
5.5 Detector/Attenuator Recalibration or Replacement ............................30
5.5.1 PROM Replacement Procedure ...................................................... 31
5.6 IEEE-488 (Model 835-IEEE) Interface Installation .................................. 31
5.7 Troubleshooting and Self Diagnostic Program ..................................... 31
Section 6 - Service
6.1 Introduction................................................................................................32
6.2 Factory Service...........................................................................................32
6.3 Component Location Drawings................................................................33
6.4 Service Form ...............................................................................................35
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List of Illustrations
2-1 Line Frequency Jumper .............................................................................. 5
2-2 Model 835 Front Panel ................................................................................ 7
2-3 Feedback Picoammeter and Signal Conditioning Circuit......................18
2-4 Wavelength Response of Silicon Detector and Attenuator ................. 21
2-5 Detector Saturation .................................................................................. 22
3-1 Interconnection of Current Source and Model 835 ...............................25
4-1 Simplified Block Diagram ..........................................................................27
6-1 Exploded View of Model 835 ....................................................................33
6-2 Mother Board Component Location Drawing ....................................... 34
List of Tables
2-1 Error Messages.............................................................................................9
2-2 Range, and Overload Conditions ............................................................ 10
3-1 Recommended Current Calibration Equipment ................................... 24
3-2 Calibration Check Table........................................................................... 25
Safety Precautions
The following safety precautions should be observed before operating the
Model 835.
This instrument is intended for use by qualified personnel who recognize
shock hazards and are familiar with safety precautions required to avoid
possible injury. Read the manual carefully before operating the instrument.
Exercise extreme caution when a shock hazard is present at the detector
input. The American National Standards Institute (ANSI) states that a shock
hazard exists when voltage levels greater than 30V RMS or 42.4V peak are
present. A good safety practice is to expect that a hazardous voltage is
present in any unknown circuit before measuring.
Do not exceed 30V RMS between the detector input connector and earth
ground.
Inspect detector leads for possible wear, cracks, or breaks before each use.
If any defects are found, replace with detector cable with one that has the
same measure of safety as the ones supplied with the instrument.
Do not connect any conducting detector housing to anything that may have
a voltage higher than 30V.
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Model 835
Laser Pico-Watt Digital Power Meter
Features:
• 4-1/2 Digit digital and 50 segment analog backlit LCD displays
• Digital wavelength response compensation
• Autoranging from 2 nW to 2 mW full scale, up to 2W with attenuator
• Linear and Log (dBm and dB) modes
• Ref Mode displays power ratio relative to stored power reference
• Choice of individually calibrated Silicon and Germanium detectors
• Analog Ouput
Options:
• Model 835-BAT Rechargeable Battery Pack
• Model 835-IEEE IEEE-488 Computer Interface
• Model 818-FA Fiber Connector Adaptor with FP3-CA series Snap-In
Fiber Connectors
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Model 835 Specifications
Electrical Accuracy Analog
18°C-28°C (1 Year) Rise Time
Range2Resolution2±(%rdg +%full scale)1(10%-90%)
2 nW 0.1 pW 0.4 +0.2 60 msec
20 nW 1 pW 0.4 +0.05 60 msec
200 nW 10 pW 0.2 +0.05 6 msec
2 mW 100 pW 0.15+0.05 3 msec
20 mW 1 nW 0.1 +0.05 3 msec
200 mW 10 nW 0.1 +0.05 1 msec
2 mW 100 nW 0.1 +0.05 1 msec
Notes:
1. When properly zeroed. Detector response between 0.1 and 1 A/W (typical for detector
w/o attenuator)
2. Divide range and resolution by order of magnitude of detector response for detector
responsive less than 0.1 A/W. For example, if detector response is 0.002 A/W, divide
range and resolution specifications by 0.001/0.1 = 0.01.
Ranging: Manual or autoranging.
Autoranging Time: Average 250 msec per range.
Settling Time at Display: Less than 1 second to within 2 counts on
fixed range.
Conversion Period: 170 msec.
Temperature Coefficient : +(0.1 x applicable accuracy specification)
(0°-18°C & 28°-50°C) per °C.
Maximum Common
Mode Voltage: 30V rms, DC to 60 Hz sine wave.
Analog Output
Output Voltage: Inverted direct amplification of the input
current. −103to 108V/A gain depending on
range selected.
Output Resistance: 1000Ω.
Front Panel Switches
Power: On and Off.
Range ▼: Selects manual range and decreases the
range.
Range ▲: Selects manual range and increases the
range.
Auto: Selects manual or autoranging.
Time Constant: Changes the effective time constant
between slow, medium and fast. Does not
affect analog output.
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Null: Stores or clears the dark or ambient light
level photodetector current. Subsequent
power readings are computed after
subtracting this current from photodetector
current.
Log/Lin: Switches between linear and logarithmic
display modes.
Ref: Stores or clears reference level. Enter or
exit ratio or dB display modes.
λCal ▼ ▲ : While held, increments (decrements) the
wavelength by 10nm steps. Detector /
attenuator serial number display.
λCal Save: Store the power-up wavelength and
attenuator status.
Attenuator: When on, includes attenuator transmission
factor in detector response used to compute
optical power.
Bar Graph: 50 segment display of value in digital
display with user selectable full scale ranges
of ±5, 25, 50, 125, 250, 500, 1250, 2500, 5000,
12500, 25000 counts and offset control.
Zoom Ρ: Increases bar graph sensitivity.
Zoom Θ: Decreases bar graph sensitivity.
Offset: Offsets the zero of the bar segment display
to the value displayed on the digital display.
Zero Check: Used to adjust zero on lowest range.
IEEE-488 Bus Implementation (Option 835–IEEE)
Multiline Commands: DCL, SDC, GET, GTL, UNT, UNL, SPE, SPD.
Uniline Commands: IFC, REN, EOI, SRQ, ATN.
Interface Functions: SH1, AH1, T5, TE0, L4, LE0, SR1, RL1, PP0,
DC1, DT1, C0, E1.
Programmable Parameters: Zero Check, Current Range, Null, Reference
Level On/Off, Wavelength, Attenuator On/
Off, Log (dBm, dB), Trigger, EOI, SRQ, Status,
Output Format, Terminator.
Readable Parameters: Power, Power Range, Wavelength, Status
Word, Probe/Attenuator Serial Number.
General
Displays: 4-1/2 digit backlit LCD, 0.5 “ height, polarity,
range, wavelength and status indication. 50
segment Analog Display with zero offset and
selectable full scale ranges of ±5, 25, 50, 125,
250, 500, 1250, 2500, 5000, 12500, 25000
counts.
Overange Indication: “OL” or “-OL” displayed.
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Connectors:
Input: BNC.
Analog Output: Banana Jacks
Operating Environment: 0-50°C, less than 70% R.H. up to 35°C;
linearly derate 3% R.H./°C up to 50°C.
Storage Environment: −25°C to +60°C.
Power: 105-125V or 210-250V (switch selected), 90-
110V available, 50-60Hz, 12VA. Optional 5
hour battery pack, Model 835-BAT.
Dimensions: 216 mm wide x 89 mm high x 267 mm deep
(8.5" x 3.5" x 10.5").
Net Weight: 2.1 kg (4.7 lbs.)
Accessories Available
Model 835-BAT: Rechargeable Battery Pack
Model 835-IEEE: IEEE-488 Interface
Model 818-SL: Large Area Silicon Photodetector
Model 818-ST: Beam Sampling Silicon Photodetector
Model 818-IR: Germanium Infrared Photodetector
Model 818-UV: Silicon Ultraviolet Photodetector
Model 818-SCAL: Detector Calibration Service
Model 818-RCAL: Detector Recalibration Service
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Section 1
General Information
This instruction manual contains the necessary information for operating
and maintaining the Model 835 Series Laser Pico-Watt Digital Power Meter
and the Model 835-BAT Rechargeable Battery Pack. This information is
divided into the following sections:
1. Section 1 contains general information and provides guidelines for
using this manual. Important safety information is also presented
here.
2. Section 2 contains detailed operating information for the Model 835
Series Power Meters.
3. Section 3 contains the information needed to verify the electronic
accuracy of the Model 835. Performance verification can be done
upon the receipt of the unit or whenever the accuracy is in question.
4. For the more technically oriented user, information on theory of
operation and maintenance is contained in Sections 4 and 5.
5. Section 6 contains information on factory service and component
location drawings.
NOTE
The Model 835-IEEE IEEE-488 computer interface and all
photodetectors come supplied with separate instruction manuals.
Perform the following steps in sequence to quickly and safely become
familiar with the basic operation of the Model 835.
1. Verify that the Model 835 was not damaged in transit, as explained in
paragraph 1.3.
2. Carefully read sections on Safety Precautions, General Information,
and Operation. Understand and observe the warnings found in these
sections.
3. Referring to paragraph 2.2.1 (Line Power) set the line voltage switch
and line frequency (if necessary) and plug the power cord into a
properly grounded outlet. If the optional battery pack is installed the
charge circuitry will be activated.
4. Become familiar with the controls and displays of the Model 835 as
follows:
A. Turn on the Model 835 by pressing in the red ON/OFF pushbutton.
F60 or F50 will be briefly displayed, followed by the detector or
attenuator serial number. F60 indicates that the unit is configured
to operate at a 60 Hz line frequency. F50 indicates that the unit is
configured for 50 Hz. Do NOT connect any detector yet.
B. The ATTENUATOR annunciator may be on. Press the ATTEN
button several times. The ATTENUATOR annunciator will turn on
and off. While in Attenuator mode, the display readings are
compensated for the optical characteristics of the attenuator. End
with the ATTENUATOR annunciator off.
Getting Started
1.2
1.1 Introduction
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C. The meter will be in autoranging mode on power up. The AUTO
annunciator will be displayed. To put the meter into manual
ranging mode, press the AUTO pushbutton. The AUTO
annunciator will turn off. Press RANGE ▲to set a less sensitive
range or RANGE ▼to set a more sensitive range. Press AUTO
again to return to autoranging. The wavelength of photodetector
responsivity data used for power calculation will be displayed in
the upper right of the digital display. followed by the nm
annunciator.
D. Press the ZERO CHECK pushbutton and note that the ZERO
CHECK annunciator turns on. Press again to turn off.
E. The Null (REL) mode can be used in the linear measurement
(watt) mode or the logarithm mode. The stored Null current level
will be subtracted from all subsequent measurements. Press the
NULL pushbutton and note that the REL (for relative) annunciator
turns on. Press again to turn off.
F. Select logarithm mode (for decibel readings) by pressing the LOG/
LIN button. The dBm annunciator will turn on. Press again to take
the Model 835 out of the decibel mode.
G. The REF (reference) button stores the reference level to be used
to calculate dB (relative) or to make ratio measurements. Press
the REF button and note that the watt (W) annunciator turns off to
indicate that the reading is a ratio. The OL (overload) annunciator
may turn on indicating that the reference level is too small or the
signal too large to give a meaningful ratio. Press the LOG/LIN
button to put the instrument in logarithmic mode, then press the
REF button. The dB annunciator will light. Press again to clear the
reference level and take the instrument out of REF mode.
H. Photodetectors have response characteristics which depend upon
the wavelength of the light incident upon them. Press the λCAL
▲(wavelength up) and hold in until the wavelength annunciator
turns off. The word PROBE will light, and the main display will
show the detector serial number. Press the ATTEN button and the
display will show the attenuator serial number, the ATTENUATOR
annunciator will light, and the PROBE annunciator will turn off.
Press the λCAL ▼(wavelength down) button and hold until the
attenuator serial number is again displayed. Press the ATTEN
button again to turn the attenuator calibration factor off.
I. The λCAL SAVE button stores the wavelength and attenuator
status as power-up conditions. See paragraph 2.7.11.
J. The TIME CONST button controls the effective time constant of
the displayed readings. Press and hold the TIME CONST button.
The TIME CONSTANT annunciator on the lower display will
change in a repeating SLOW, MED, FAST sequence.
K. The group of buttons below the bar segment display control the
zero and resolution of the bar segment display. The OFFSET
button sets the zero of the bar display to the digital reading when
the OFFSET button is pressed. Press the analog display OFFSET
button. The OFFSET annunciator in the lower display should light.
Press again to reset the bar display zero. The ZOOM buttons
control the resolution and range of the bar display. The numbers
at the end of the bar display indicate the range. Depress and hold
the ZOOM out <button until the number at the ends of the bar
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segment display is 25000. Momentarily depress the ZOOM in Ρ
button. The number at the end of the display will change to 12500.
Press and hold until that number is 5. Depress and hold the
ZOOM out Θuntil the full scale range of the bar graph is +25000
counts.
NOTE
In this manual the term “counts” refers to an increment of one in
the least significant digit of the digital display. For example, if the
digitaldisplayread1.9453mW,1countis0.0001 mW. If the display
reads –23.45 dB, 1 count is 0.01 dB.
Connect the detector in normal room lights and familiarize yourself with
the operation of the instrument following the steps above as a guide.
When you are comfortable with the controls of the Model 835, go on and
make the desired measurements using Section 2, Operation as a guide.
The Model 835 Laser Pico-Watt Autoranging Power Meter was carefully
inspected mechanically, electrically, and optically, before shipment. Upon
receiving the Model 835, check for any obvious signs of physical damage
that might have occurred during shipment. Report the damage to the
shipping agent immediately. Retain the original packing materials in case
reshipment becomes necessary. The following items are included with
every Model 835 order:
• Model 835 Laser Pico-Watt Autoranging Power Meter
• Photodetector (some models include stand)
• Photodetector Manual and Calibration Certificate
• Model 835 Instruction Manual
• Additional Accessories and Options as included
Detailed Model 835 specifications may be found immediately preceding the
table of contents of this manual.
Warranty information may be found on the inside front cover of this
manual. Should it be necessary to exercise the warranty, contact your
Newport representative or the factory to determine the correct course of
action. Newport Corporation maintains offices in the United States and
worldwide. Information concerning the application, operation, or service of
your instrument may be directed to any of these locations. Check the back
cover of this manual for offices and their addresses.
Information concerning improvements or changes to the instrument which
occur after the printing of this manual will be found on the addendum sheet
included with this manual. Be sure to review these changes before
attempting to operate or service the instrument.
Unpacking and
Inspection
Specifications
Warranty Information
1.3
1.5
1.4
Manual Addenda
1.6
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The following safety symbols and terms are used in this manual or found on
the Model 835.
The symbol
!
on the instrument indicates that the user should refer to
the operating instructions in this manual.
The WARNING heading in this manual explains dangers that could result in
personal injury or death.
The CAUTION heading in this manual explains hazards that could damage
the instrument.
The following accessories can be used with the Model 835.
Model 818-SL Silicon Photosensor — A 1 cm2aperture silicon photodiode
packaged to facilitate mounting and accept fiber adapters. Useful spectral
range 400-1100 nm. Includes detachable attenuator.
Model 818-UV Silicon Photodiode — A 1 cm2aperture silicon photodiode
packaged to facilitate mounting and accept fiber adapters. Useful spectral
range 250-1100 nm. Includes detachable attenuator.
Model 818-ST Silicon photosensor — A handheld silicon photosensor in a
very thin package especially useful for measuring power in hard to reach
places. Includes sliding OD-3 attenuator.
Model 818-IR — A 3 mm diameter Germanium photosensor with a post
mountable housing capable of accepting filters and fiber adapters. Useful
spectral range 800-1800 nm. Includes detachable attenuator.
Model 883 Series Attenuators — Replacement attenuators for use with the
Model 818-SL, 818-UV, or 818-IR photosensor.
Model 835-BAT Rechargeable Battery Pack — Provides a minimum of 5
hours operation from full charge, recharges within 10 hours and is field
installable.
Model 835-IEEE Computer Interface — IEEE-488 standard interface option
provides isolated data output and instrument control. Switch-selectable
talk only or addressable modes. Mounts within and is powered by the
Model 835.
Calibration - Newport maintains a National Institute of Standards and
Technology (NIST) traceable spectrophotometric calibration facility.
Photodetectors are recalibrated on a fee for service basis. In addition,
special calibration services can be arranged. Contact Newport for details.
Safety Symbols
and Terms
1.7
1.8 Optional Accessories
and Services
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Section 2
Operation
This section contains the information needed to prepare and operate the
Model 835 as a power meter. Bench operation consists of using the Model
835 to perform basic optical power measurements. Using the instrument to
compensate for dark current and ambient light, as well as making ratio and
logarithmic (dBm, dB) measurements, is also covered. The capabilities of
the Model 835 can be enhanced with the addition of then Model 835-IEEE
interface. IEEE-488 computer interface operation is covered in the Model
835-IEEE Instruction Manual.
2.2.1 Line Power
The Model 835 is provided with a three-wire line cord which mates with
third wire grounded receptacles. Connect the instrument to AC line power
as follows:
1. Set the LINE VOLTAGE switch on the back of the instrument to
correspond to line voltage available. Ranges are 105-125V or 210-250V
50/60Hz AC. If the Model 835 is ordered with the 90-100V operation
option, a label on the back panel will indicate that the meter is
configured for 100V operation.
CAUTION
Connect only to the line voltage selected. Application of incorrect
voltage can damage the instrument.
2. If 50 Hz operation is desired, open the top cover of the instrument
(see paragraph 5.2), and connect the line frequency jumper as shown
below. Units are normally shipped configured for 60 Hz operation as
indicated by the F60 display immediately after power-up.
VIEW FROM REAR
50 Hz 60 Hz
Figure 2-1 50/60 Hz Selection Jumper
3. Plug the power cord into a properly grounded outlet.
WARNING
Ground the instrument through a properly grounded receptacle
before operation. Failure to ground the instrument can result in
severe injury or death in the event of short circuit or malfunction.
Introduction
2.1
Preparation for use
2.2
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NOTE
Although the Model 835 is specified at 50 Hz and 60 Hz, the
instrument may be operated at 400 Hz and 440 Hz. Add 10 counts
to instrument specifications under this condition.
2.2.2 Battery Pack Power
The Model 835 may also be operated from rechargeable sealed nickel-
cadmium batteries contained in the optional Model 835-BAT Rechargeable
Battery Pack. A fully charged battery pack will operate the Model 835 for
five hours. The BAT annunciator will turn on when the battery charge is
insufficient to maintain accurate readings. Refer to Section 5, paragraph
5.3 for installation procedures.
2.2.3 Battery Charging
After the Model 835-BAT Battery pack is installed in the Model 835 it can be
charged and recharged as follows:
1. Connect the instrument to line power as described in paragraph 1.2.
2. With the power switch off, the battery charge circuitry is
automatically energized to charge the battery at the maximum rate.
When the battery pack is first installed, or if it is completely
discharged, allow it to charge for ten hours.
NOTE
For maximum battery efficiency only charge the battery pack after
it has become discharged and only charge until it is fully charged
(10 hours). Continuous charging over long periods of time will not
damage the batteries, but useful life will gradually decrease. This
loss is not permanent and may be restored by cycling the battery
pack through several complete charge/discharge cycles. The
battery pack is capable of 500 to 1000 charge/discharge cycles
before replacement is needed.
Do not make measurements with the BAT annunciator on as the
readings may be erroneous.
3. When the Model 835 is in use on line power, the battery charger
maintains a trickle charge on the battery pack.
The Model 835 is equipped with a tilt bail which makes it possible to elevate
the instrument to a convienent viewing position. To elevate the instrument
pull the bail on the bottom of instrument out until it locks in position.
2.3 Tilt Stand
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7
2.4 Model 835
Familiarization
The following paragraphs and Figure 2-2 provides a brief description of the
display, front panel controls and connectors.
Figure 2-2 Model 835 Front Panel
2.4.1 Digital Display
The Model 835 has a 4-1/2 digit backlit liquid crystal display (LCD). The
minus sign is displayed. The plus sign is implied by the absence of the
minus sign. The following annunciators are displayed on the LCD.
BAT — Low battery indicator for the Model 835-BAT.
nW, mW, mW, or W— Nanowatts, microwatts, milliwatts, or watts display
range selected.
dBm, dB — Decibels relative to 1 mW (dBm) or decibels relative to user set
level (dB) selected.
When neither watts or decibels displayed — Value displayed is a linear
ratio referenced to user set power.
RMT (Remote) — Model 835 being controlled over the IEEE-488 bus (Model
835-IEEE installed).
AUTO — Autorange selected.
REL —Null selected.
ZERO CHECK — Zero Check selected.
nm — Follows wavelength used to determine detector responsivity used to
compute optical power from detector photocurrent. If NOT displayed,
detector or attenuator serial number is displayed.
ATTENUATOR — Indicates attenuator selected. When in serial number
display mode, indicates that attenuator serial number is displayed.
PROBE — Indicates detector serial number is displayed.
CAL — Model 835 in current calibration mode. This is normally a factory
procedure.
125000 0 125000
OFFSET
TIME CONSTANT
SLOW MED FAST
–+
nW
µW
mW
BAT
PROBE CAL
nm
dBm REL
ATTENUATOR
RMT LLO
ZERO CHECK
AUTO
On
Off
Save
Auto
Null Log
/ Lin Ref
Offset
Zoom
Time
Const. Attn.
Zero
Check
Detector
Zero
■Optical Power Meter ■
Model 835
λCAL
DISPLAY MODE
RANGE
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