Digital Photometer
Operator’s Manual
Model Numbers:
IF PM
Industrial Fiber Optics
*
Copyright © 2023
Previous Printings 2012, 2009, 2008, 2006, 2004, 2001
by Industrial Fiber Optics, Inc.
Revision - G
Printed in the United States of America
* * *
All rights reserved. No part of this publication may be reproduced,
stored in a retrieval system, or transmitted in any form or by any means
(electronic, mechanical, photocopying, recording, or otherwise)
without prior written permission from Industrial Fiber Optics.
* * * * *
INTRODUCTION
This manual provides information about Industrial Fiber Optics’ Digital
Photometer. It contains all the information you need to operate this device safely
and knowledgeably, even if you are a novice to this technology. Please read the
manual carefully before operating.
As soon as you receive this laser, inspect it and the shipping container for
damage. If any damage is found, immediately refer to the section of this manual
entitled SHIPMENT DAMAGE CLAIMS.
Industrial Fiber Optics makes every effort to incorporate state-of-the-art
technology, highest quality and dependability in its products. We constantly
explore new ideas and products to best serve the rapidly expanding needs of
industry and education. We encourage comments that you may have about our
products, and we welcome the opportunity to discuss new ideas that may better
serve your needs. For more information about our company and products refer to
www.i-fiberoptics.com.
Thank you for selecting this Industrial Fiber Optics product. We hope it
meets your expectations and provides many hours of productive activity.
Sincerely,
The Industrial Fiber Optics Team
–i–
– ii –
TABLE OF CONTENTS
Introduction……………………….................…….....…………..……
i
LASER CLASSIFICATIONS............................................................
iv
BACKGROUND................................................................................
1
GENERAL INFORMATION........….............................……...……....
2
Control/Display Unit....................................................................
2
PRODUCT SPECIFICATIONS…………................….......................
5
SAFETY….............................................................................……….
6
Electrical......................................................................................
6
Optical..........................................................................................
6
INITIAL CHECKOUT…................................................................…
7
OPERATING PROCEDURES….......................................................
8
Monitoring Solar Energy..............................................................
8
Measuring a Laser Beam’s Power...............................................
8
TROUBLESHOOTING…......................................................……….
9
SERVICE AND MAINTENANCE.....….............................……..…...
10
Battery Installation.......................................................................
10
“Zeroing” Procedure...................................................................
11
Malfunctions.................................................................................
11
WARRANTY.....................................................................................
12
SHIPMENT DAMAGE CLAIMS.......................................................
13
– iii –
LASER CLASSIFICATIONS
All manufacturers of lasers used in the United States must conform to regulations administered by the Center for Devices and Radiological Health (CDRH), a branch of the U.S.
Department of Health and Human Services. CDRH categorizes lasers as follows:
Class
Description
I
A laser or laser system, which does not present a hazard to skin
or eyes for any wavelength or exposure time. Exposure varies
with wavelength. For ultraviolet, 2 to 4 µm exposures is less than
from 8 nW to 8 µW. Visible light exposure varies from 4 µW to 200
µW, and for near-IR, the exposure is < 200 µW. Consult CDRH
regulations for specific information.
II
Any visible laser with an output less than 1 mW of power. Warning
label requirements – yellow caution label stating maximum output
of 1 mW. Generally used as classroom lab lasers, supermarket
scanners and laser pointers
IIIa
Any visible laser with an output over 1 mW of power with a
maximum output of 5 mW of power. Warning label requirements
– red danger label stating maximum output of 5 mW. Also used
as classroom lab lasers, in holography, laser pointers, leveling
instruments, measuring devices and alignment equipment.
IIIb
Any laser with an output over 5 mW of power with a maximum
output of 500 mW of power and all invisible lasers with an output
up to 400 mW. Warning label requirements – red danger label
stating maximum output. These lasers also require a key switch
for operation and a 3.5-second delay when the laser is turned on.
Used in many of the same applications as the Class IIIa when
more power is required.
IV
Any laser with an output over 500 mW of power. Warning label
requirements – red danger label stating maximum output. These
lasers are primarily used in industrial applications such as tooling,
machining, cutting and welding. Most medical laser applications
also require these high-powered lasers.
– iv –
BACKGROUND
The word “photometer” originates from two other words — photo, which means light,
and meter, which means instrument. Together the two words mean “an instrument for
measuring light.”
Photometers (or light meters) are used in many household and commercial applications,
including some we may not be aware of. For example, the “night lights” in the hallway
outlets of many modern homes contain a photometer. When it gets dark, a photometer
sensor switches an electrical device that supplies electricity to a light source. Another
common photometer is the optical sensor in many point-and-shoot cameras. It is an internal
photometer combined with sophisticated electronics that control the lens opening and
shutter speed necessary to produce high-quality pictures.
The Digital Photometer to which this manual applies is a simple, easy-to-use digital
instrument for measuring the energy levels of visible and some near-infrared light beams.*
It was designed for instructors, students and technicians. Applications of the photometer
include science, physics, principles of technology and vocational technology programs.
Typical experiments that teachers and students may conduct using this photometer include:
•
Characterizing the polarization of light
•
Monitoring solar energy
•
Optical filter transmission measurements
•
Demodulating a laser beam
•
Measuring attenuation in fiber optic cables
For more details about the specifications and use of the photometer, continue to the next
section.
Table 1. Common abbreviations used in this manual.
Abbr
Long version
Scientific Notation
mW
milliwatts
1 x 10-3 watts
µW
microwatts
1 x 10-6 watts
nW
nanowatts
1 x 10-9 watts
mm
millimeters
1 x 10-3 meters
µm
micrometers
1 x 10-6 meters
nm
nanometers
1 x 10-9 meters
* More information is provided on page 5, under Product Specifications.
–1–
GENERAL INFORMATION
Control / Display Unit
1. ON/OFF Switch
The ON/OFF Switch is located in the lower left portion of the Digital Photometer’s
face. It is a “momentary switch” that applies power to the Control/Display Unit and
Detector Assembly from the internal batteries only when the switch is pressed or
closed. (The switch’s momentary feature prevents the user from inadvertently leaving the photometer on and draining its internal batteries.)
2. Selector Switch
The Selector Switch is located in
the lower middle face of the meter.
It is used to select the meter’s
four different power ranges: 20
microwatts (µW), 200 microwatts,
2 milliwatts (mW) and 20
milliwatts. Position of the selector
switch does not control electrical
power to the meter.
3. Display (LCD)
PHOTOMETER
3
6
ZERO
V+
4
V-
5
200 µW 2 mW
20 mW
20 µW
2
PUSH AND
HOLD
1
SELECTOR
SWITCH
ON/OFF
SWITCH
The indicator for the Digital
Industrial Fiber Optics
Photometer is a liquid crystal
1339
display (LCD) with 3-1/2-digit
Figure 1. Photometer face.
resolution. The maximum display reading
is 1999 and the minimum is 0. (When the meter displays a negative number, go to
the section entitled “Zeroing” Procedure on Page 11 to correct the reading.)
4. V+ Jack
The V+ jack is an industry-standard “banana” as is the V- jack. Both are located on
the middle right portion of the Display/Control Unit face. The voltage across the
V+ and V- jacks is an analog equivalent to the reading on the LCD display. The jacks
provide access to the internal electronics and a positive voltage corresponding to the
amount of light striking the sensing element (Detector). Full-scale reading on the
digital display will correspond to one volt across the V+ and V- banana jacks.
The V+ and V- banana jacks make the meter useful as a transducer to convert an
optical signal to an electrical signal. The jacks can be connected to an oscilloscope,
multimeter, chart recorder or a preamplifier and speaker.
–2–
5. V- Jack
The V- jack is also an industry-standard “banana” located in the middle right portion
of the photometer face. This banana jack completes the electrical circuit for the V+
banana jack.
6. Cable
The cable electrically connects the
Control/Display Unit to the Detector Assembly. Do not disassemble
or remove the cable from either
assembly as product warranty will
be voided
7. Stand
The Digital Photometer is accompanied by a metal stand for mounting
the Detector Assembly. The stand
allows the Detector Assembly to be
raised and lowered, which makes
measurements easier, more stable
and more uniform.
8. Detector Assembly
The Detector Assembly is composed
Figure 2. Front view of the Detector
of three parts: the Detector HousAssembly mounted on its stand.
ing, Detector (the optical sensor),
and a thumb screw. The Detector
Assembly is electrically and mechanically connected to the Control/Display Unit by
the Cable. It is not meant to be removed from the cable, and your product warranty
will be voided if it is removed.
9. Detector
The Detector, or light sensing element, is approximately one centimeter square
with a 7 mm diameter aperture in the center of the Detector Housing. See Figure
2. Always align your light source with the detector to make the most accurate
measurements.
10. Thumb Screw
The thumb screw is located on the side of the Detector Housing. Loosen the screw
to adjust the Detector Assembly on the stand and tighten the screw to secure the
housing at the desired elevation. Tighten this screw as you would turn off a water
faucet. Do not overtighten as this will damage the threads and/or detector mount.
–3–
11. Batteries (Not shown)
The Digital Photometer requires two 9-volt batteries (included) for operation. For
shipping and storage purposes they have not been installed at the factory. To install
or replace the batteries, follow the procedure in the section entitled SERVICE AND
MAINTENANCE.
Battery types suggested for use with this meter include standard, heavy duty,
and alkaline 9-volt batteries. Part numbers for major manufacturers are shown in
Table 2. Do not use nickel-cadmium (NiCd) or lithium chemistry batteries in this
instrument. They may damage your meter and/or produce inaccurate readings.
Table 2. Part numbers for popular batteries suitable for the Digital Photometer.
Standard
Heavy-duty
Alkaline
Not available
M9V
MN1604
Eveready®
216
1222
522VP
Ray-o-Vac
1604
D1604
A1604
Duracell®
®
–4–
PRODUCT SPECIFICATIONS
Table 3. Digital Photometer specifications.
Parameter
Value
Operating
Input power
2 9-V batteries
Accuracy*
± 10%
Range (4)
19.99 µW, 199.9 µW, 1.999 mW, 19.99 mW
Temperature
10 to 30° C
Optical
Detector active area
38 mm2
Aperture
7 mm
Wavelength sensitivity
450 to 1050 nm
Maximum optical input
20 mw
Storage
16 x 9.5 x 6.5 cm
Detector Assembly Stand
16.5 x 5 cm
Weight
750 grams
Temperature
-10 to 50° C
100
1344.eps
NORMALIZED RESPONSE (PERCENT)
Control/Display unit
90
80
70
60
50
40
30
20
10
0
300
400
500
600
700
800
WAVELENGTH (NANOMETERS)
900
1000
Figure 3. Typical response of Detector versus wavelength.
* Calibrated at 635 nm. Consult factory for calibration at other wavelengths.
–5–
SAFETY
Electrical
This meter is particularly safe because it operates from low voltage batteries. However, as
when using any electrical device, certain safety precautions are imperative:
•
Do not short-circuit the banana jacks or connect them to any high voltage.
•
Do not operate this instrument while in contact with water.
•
Use only recommended batteries.
• Do not modify any of the electrical circuitry in the photometer. (Modifying
circuitry will also void your product warranty.)
Optical
There are no optical safety hazards associated with the Digital Photometer. However,
because this instrument and others like it are often used in conjunction with lasers or other
high-intensity light sources, it is necessary to be familiar with their operating procedures. If
you are uncertain or unfamiliar with them, review their operating manuals or contact your
instructor or safety officer.
–6–
INITIAL CHECKOUT
1.
Unwrap all the components from the protective shipping packaging. Do
not throw away the 12 x 6 x 4 tuck-top box, as it can be used to store the
Digital Photometer.
2.
Check that the Digital Photometer is complete and in good, undamaged
condition. The complete meter includes the Control/Display Unit, Detector
Assembly, Stand and two 9-volt batteries.
3.
Install the batteries following the procedure found in the section entitled
SERVICE AND MAINTENANCE.
4.
Set the Stand upright, loosen the Thumbscrew at the rear of the Detector
Assembly and slide the Detector Assembly over the post. Secure the
Detector Assembly in place by tightening the Thumbscrew. Do not
overtighten the Thumbscrew.
5.
Turn the Selector Switch to 2 mW (milliwatts).
6.
Turn the Control/Display Unit on by depressing the ON/OFF switch
located in the lower left portion of the face. Numbers on the LCD display
should now be visible.
7.
Hold the ON/OFF switch in for 15 seconds. If the LCD does not
read zero (± .002 mW) , refer to the section entitled SERVICE AND
MAINTENANCE for the procedure to “zero” the Control/Display Unit.
8.
Point the Detector Assembly at a light source. Depress and hold the ON/
OFF switch in. The display should read between 50 µW and 1 mW for
typical lighting.
9.
Shade the detector inside the Detector Assembly from the room light and
observe a reduction in the LCD display’s reading.
You should have now verified that the Digital Photometer has arrived in good physical
condition and is electrically/optically ready to use. Following are sample procedures using
this photometer to monitor solar energy and power levels of laser beams.
–7–
OPERATING PROCEDURES
Monitoring Solar Energy
Using the Digital Photometer in solar experiments is just one of many applications for this
versatile instrument. Below is a set-up procedure for monitoring solar energy.
1.
Set the Selector Switch to the 20 mW position.
2. Check that the meter reads zero (± .002 mW) when the detector is
covered and the On/Off Switch is closed. If not, go to the section titled
“Zeroing” Procedure under Service and Maintenance.
3.
Point the Detector Housing directly at the sun. (This can be done with the
Detector Housing on or off the stand.)
4.
Depress and hold the ON/OFF Switch in on the Control/Display Unit for
15 seconds.
5.
Adjust the position of the Selector Switch so that the most sensitive position is used without “overranging” the meter.
6.
Note the reading on the Control/Display Unit’s LCD.
Measuring a Laser Beam’s Power
1. Review your lab’s laser safety procedures.
2. Set the Photometer’s Selector Switch to the 20 mW position and zero the
meter if necessary.
3.
Set the laser up and position it so the emitted beam can not accidentally
create a hazard for you or other people in the vicinity.
4.
Switch the laser on and open its beam shutter.
5.
Align the laser beam with the Detector inside the Detector Housing, being
very conscious of safety.
6.
Depress and hold in the ON/OFF Switch on the Control/Display Unit for
15 seconds.
7.
Adjust the position of the Selector Switch so that the most sensitive position is used without “overranging” the meter.
8.
Note the reading on the Control/Display Unit’s LCD.
–8–
TROUBLESHOOTING
LCD Remains Blank When Switch is Pressed
•
On/Off Switch is not depressed fully.
•
No batteries installed.
•
Batteries may be weak. Replace batteries. See section entitled SERVICE
AND MAINTENANCE for battery installation procedure.
LCD Display Does Not Read Zero
•
Cover detector aperture.
•
Zero adjustment needs to be made. See section entitled SERVICE AND
MAINTENANCE for corrective procedure.
•
Batteries may be weak. Replace batteries. See section entitled SERVICE
AND MAINTENANCE for battery installation procedure.
No Change in Display Reading
•
Light source or laser beam not striking the detector’s sensitive area inside
Detector Assembly. Reposition Detector Assembly or light source.
•
Selector Switch is set at too high a level. Turn Selector Switch counterclockwise one stop.
•
Batteries may be weak. Replace batteries. See section entitled SERVICE
AND MAINTENANCE for battery installation procedure.
No Output from Banana Jacks
•
On/Off Switch is not depressed fully.
•
Light source or laser beam not striking the
detector’s sensitive area inside Detector
Assembly. Reposition Detector Assembly or light
source.
•
Selector Switch is set at too high a level. Turn
Selector Switch counter-clockwise one step.
•
Selector Switch is set at too low a level. Turn
Selector Switch clockwise one step.
•
Batteries may be weak. Replace batteries.
See section entitled SERVICE AND
MAINTENANCE for battery installation
procedure.
•
The electrical load of the device attached to the
banana jack outputs is too low. (These outputs
were not designed to drive an audio speaker.)
–9–
Do not attempt to
troubleshoot the Digital
Photometer beyond
the steps listed above.
If you believe that a
problem exists within
the Digital Photometer,
please either contact the
factory or return it for
appropriate servicing to
Industrial Fiber Optics,
as described in the section on SERVICE AND
MAINTENANCE
SERVICE AND MAINTENANCE
The only service and maintenance that the Digital Photometer should require is battery
replacement and “zeroing.” Instructions for both procedures follow. All other adjustments
have been made at Industrial Fiber Optics facilities.
Battery Installation
The recommended batteries for this meter are standard, heavy-duty or alkaline 9-volt
batteries. See Table 2 for the part numbers of major battery manufacturers. Do not use
nickel-cadmium or lithium chemistry batteries in this meter as they may cause damage or
malfunctions.
1.
Remove the four screws at the corners of the Control/Display Unit
front panel.
2.
Lift the front panel from the meter chassis and place it on a table or bench,
face down.
3.
Remove both batteries from the battery holders by tipping the rear portion
upward and outward.
4.
Remove any protective packaging from the replacement batteries.
5.
Place one 9-volt battery into one of the battery holders and securely push it
into place. When the battery is positioned properly it will be level with, and
reside just below, the plastic battery holder sides.
6.
Install the other 9-volt battery.
7.
Check to ensure that the battery holder and 9-volt terminals are
fully engaged.
8.
Place the front panel inside the chassis.
9.
Press the ON/OFF switch in to check for proper operation.
10.
Replace the four screws in the corners of the front panel and tighten them.
– 10 –
“Zeroing” Procedure
Periodically it may become necessary to adjust the Control/Display Unit so it reads zero.
in the absence of light. (When the meter is on the 20 μwatt scale the display sometimes
cannot be totally zeroed because of stray ambient light. In those cases, subtract the DC
offset from your readings.) Zeroing the Photometer can be done using the
following procedure.
1.
Cover the Detector Assembly.
2.
Turn the Selector Switch to the position at which you wish to zero
the meter.
3.
Depress and hold the ON/OFF Switch in so the meter is powered.
(The LCD display should be lit.)
4.
Let the meter stabilize for 15 seconds.
5.
Insert a small NON-METALLIC screwdriver (standard blade type) into
the hole marked Zero on the Photometer faceplate and adjust the
internal potentiometer so the LCD reads as close to 0 as possible. This
potentiometer turns only 3/4 of a revolution. Do not turn more than 3/4
of a turn or permanent damage to the meter will result.
Malfunctions
In the unlikely event that the meter malfunctions, you may have it repaired by doing the
following:
Contact us to request an RMA number.
•
Pack the Control/Display Unit, Detector Assembly, Stand, manual and your
letter carefully in a strong box with adequate packing material, to prevent
damage in shipment.
•
Ship the package with the assigned RMA number to:
Industrial Fiber Optics
1725 West 1st Street
Tempe, AZ 85281-7622
– 11 –
WARRANTY
Industrial Fiber Optics products are warranted against defects in materials and workmanship for 90 days. The warranty will be voided if internal or external components have been
damaged, mishandled, or altered by the buyer.
Warranty liability is limited to repair or replacement of any defective unit at the company’s
facilities, and does not include attendant or consequential damages. Repair or replacement
can be made only after failure analysis at the factory. Authorized warranty repairs are made
at no charge, and are guaranteed for the balance of the original warranty.
Industrial Fiber Optics offers to pay the return freight for warranty repair within the continental United States by United Parcel Service. Any other delivery means must be paid for by
the customer.
The costs of return shipments for a Digital Photometer no longer under warranty must be
paid by the customer. If an item is not under warranty, repairs will not be undertaken until
the cost of such repairs have been prepaid by the customer. Typical repair costs start at $65
and repairs usually take 1 to 2 weeks to complete.
When returning items for analysis and possible repair, please do the following:
Contact us to request an RMA number.
•
Pack the laser, power adapter, manual and letter carefully in a strong box
with adequate packing material to prevent damage in shipment.
•
Ship the package with provided RMA number to:
Industrial Fiber Optics
1725 West 1st Street
Tempe, AZ 85281-7622
– 12 –
SHIPMENT DAMAGE CLAIMS
If damage to an Industrial Fiber Optics product should occur during shipping, it is imperative that it be reported immediately, both to the carrier and the distributor or salesperson
from whom the item was purchased. DO NOT CONTACT INDUSTRIAL FIBER OPTICS.
Time is of the essence because damage claims submitted more than five days after delivery
may not be honored. If shipping damage has occurred during shipment, please do the following:
•
Make a note of the carrier company, the name of the carrier employee, the
date and the time of the delivery.
•
Keep all packing material.
•
In writing, describe the nature of damage to the product.
•
In cases of severe damage, do not attempt to use the product (including
attaching it to a power source).
•
Notify the carrier immediately of any damaged product.
•
Notify the distributor from whom the purchase was made.
– 13 –
12 0105
Rules for Laser Safety
•
Lasers produce a very intense beam of light. Treat them with respect. Most
educational lasers have an output of less than 3 milliwatts, and will not harm the
skin.
•
Never look into the laser aperture while the laser is turned on! PERMANENT
EYE DAMAGE COULD RESULT.
•
Never stare into the oncoming beam. Never use magnifiers (such as binoculars or
telescopes) to look at the beam as it travels – or when it strikes a surface.
•
Never point a laser at anyone’s eyes or face, no matter how far away they are.
•
When using a laser in the classroom or laboratory, always use a beam stop, or
project the beam to areas, which people won’t enter or pass through.
•
Never leave a laser unattended while it is turned on – and always unplug it when
it’s not actually being used.
•
Remove all shiny objects from the area in which you will be working. This
includes rings, watches, metal bands, tools, and glass. Reflections from the beam
can be nearly as intense as the beam itself.
•
Never disassemble or try to adjust the laser’s internal components. Electric shock
could result.