AV2498C Optical Multimeter
User Guide
The 41st Institute of China Electronics Technology Group
Corporation
Preface
Thank you very much for choosing the AV2498C
Optical Multimeter which is produced by the 41st Institute
of China Electronics Technology Group Corporation
(abbreviated as CETC41)! This product has higher
price-performance ratio than other products alike due to the
robust structure and simple operation. Please read this
Guide carefully for your convenience. We will do our
utmost to meet your needs, provide you with high quality
measurement instruments, as well as first-class after-sales
service. Our principle is “excellent quality, courteous
service”. To provide satisfactory products and service is our
commitment to the users. We sincerely welcome your
inquiry：
Toll-free phone: 800－8687041
Website: http://www.ei41.com
HQ(Bengbu)
Service & consultation: 0552－4072248
Technical Support: 0552-4071248
Quality Supervision: 0552-4078248
FAX:0552-4082977
Email:eibb@ei41.com
ADD: No.726 Huaguang Avenue, Bengbu, Anhui
Post Code:233006
Branch Institute (Qingdao)
Service & consultation:0532－86889847
Technical Support: 0532－86889847
Quality Supervision: 0532－86886614
FAX: 0532－86889056
Email:eiqd@ei41.com
ADD: No.98, Xiangjiang Rd, Qingdao
Economic&Technological Development Zone,Shandong
Post Code:266555
Statement
This is the first edition of User Guide of AV2498C
Optical Multimeter. The version number is
AV2.714.1291SS1.
The contents in this Guide are subject to change
without notice.
The right to interpret the contents and terms of
this Guide belongs to CETC41.
This Guide comes without a guarantee from
CETC41, including, but not limited to, the implied
warranty of merchantability and fitness for a particular
purpose. In no event shall CETC41 be liable for special,
incidental, or consequential damages.
The copyright of this Guide belongs to CETC41.
No unit and individual shall revise or distort this
manual without authorization. The Guide shall not be
reproduced and transmitted in any form (including
electronic storage, a retrieval system or translation to
other languages) for the purpose of profit. CETC41
reserves the right to take legal action for the tort.
Ann
ounc
eme
nt：
Any attempt to disassemble or modify any components not
illustrated in this Guide is not allowed. If so, degradation of
electromagnetic shielding effectiveness and damages of
internal components will impact reliability of AV2498C
Optical Multimeter. CETC41 offers no free repair even
though the warranty period is still valid.
April 10th,2016
Table of Contents
Chapter OneOverview ………………………………………1
Chapter TwoAppearance and operation instructions............... 7
Section OneAppearance and keypad ...... ……………….8
Section TwoOperation Instructions ..... ………………..17
Chapter ThreeOperating principles and technical
specifications ......................................................................... 27
Section OneOperating principles .................................. 27
Section Two Technical specifications............................ 29
Chapter FourMaintenance and repair .................................... 33
Chapter One Overview
1
Chapter One Overview
1.1 Multimeter overview
AV2498C is a handheld meter, enjoys innovative
structure and small size. The optical detector is built inside
your convenient usage. The multimeter has a rechargeable
battery inside, and dry cell batteries can also be used for
field work. When using as a light source, the multimeter is
also a system enabling loss parameters measurements of
optical fibers, cables, optical passive components etc.
AV2498C multimeter deploys a high-quality
low-noise photodiode as the optical detector, and
Chapter One Overview
2
microcontrollers for control, which is powerful in functions,
reliable in performance, competitive in price-performance,
small in size and neat in appearance. It is suitable for
construction and maintenance of optical fiber
communication projects, and an ideal optical power and
optical loss measurement instrument in scientific research,
production and mathematics fields. For high power tests,
please choose a power meter with the measurement range
of -50dBm～+26dBm.
1.2 Multimeter composition
Here are three options for the power meter modules of
Chapter One Overview
3
AV2498Cmultimeter. The power meter has two types based
on different power detecting ranges, as shown in Table 1-1.
Table 1-1 Module types of the power meter of AV2498C
Optical Multimeter
Module
No.
P1
P2
P3
Power
range
-70dBm～
+3dBm
-50dBm～
+26dBm
-50dBm～
+3dBm
The light source offers two central wavelengths, as
shown in Table 1-2.
Table 1-2 Light source types of AV2498C Optical
Chapter One Overview
4
Multimeter
Central
wavelengths
1310nm±20nm
1550nm±20nm
Output
optical
power
≥-3dBm
≥-3dBm
This Guide contains four chapters.
Chapter One introduces applications and
characteristics of AV2498Cmultimeter.
Chapter Two introduces appearance and operation
instructions of AV2498Cmultimeter.
Chapter One Overview
5
Chapter Three introduces fundamental operating
principles and technical specifications
ofAV2498Cmultimeter.
Chapter Four introduces maintenance and simple
troubleshooting of AV2498Cmultimeter.
Chapter One Overview
6
We sincerely hope our products can bring you
convenience and efficiency. Please contact us if you
encounter any problems during operation.
Chapter Four Maintenance and Repair
7
Chapter Two Structure and Operation Instructions
The keypad is used for control and setting and an
LCD is for display. Three power sources are available for
AV2498Cmultimeter, including a rechargeable battery, a
power adapter or any other systems connecting to USB
interface for power supply. Three AA dry cell batteries can
also supply power for the multimeter when the said sources
are not available. It is able to store, review results and
communicate with host computers.
Chapter Four Maintenance and Repair
8
Section One Appearance
1 Front and rear panels and keys illustrations
The front and rear panels are shown in Fig. 2-1.
Chapter Four Maintenance and Repair
9
a)
b)
c)
d)
e)
f)
h)
i)
g)
Fig. 2-1 Front and rear panels
a）【 Power】： power switch. The charge indicator is
Chapter Four Maintenance and Repair
10
under the【Power】switch. The battery is charging
when the indicator is lit, and finishes charge when
the light is out.
b）【 Zero】： press this key for zero. This function is
enabled only when the port protector is closed or
light is absent. It can delete the record being
checked during data review.
c ）【 λ 】： to set up wavelengths at
1550nm,850nm,1300nm, 1310nm in order. It can
check the previous record during data review.
d）【 Protector】： to protect the light interface.
Chapter Four Maintenance and Repair
11
e）【 Display】： to display optical power measurement
results and all indications.
f ）【 Store 】： press this key to save logarithm
measurement results. Press it to exit the review
mode.
g）【 dBm/dB/W】： to switch between measurement
modes. Logarithm measurement is the default
mode when the multimeter is power-on. Press it to
switch between logarithm measurement（dBm）,
relative measurement （ dB ） and linearity
measurement（W）, the switching sequence is:
Chapter Four Maintenance and Repair
12
Logarithm measurement Relative measurement
Linearity measurement Logarithm measurement
h）【 Data】： to review data. Press this key to display
final results stored. Serial number of the current
data and number of stored data will be displayed at
the top of the screen, the format is S/N/No. Press
【λ】 and 【Data】 to view data by Page Up and
Page Down. Press 【Save】 to return AV2498C
multimeter back to automatic measurement. Press
this key to check the next record during data
review.
Chapter Four Maintenance and Repair
13
i）【 Backlight】： press this key to switch on the LCD
backlight. Hold it down to enter light source mode
and display wavelength of the current light source
at the screen bottom. After the light source mode is
activated, press this key to adjust wavelengths of
light sources following 1550nm and 1310nm,.
After the multimeter is turned on, the LCD shows
currently measured wavelength, measurement
mode and battery level.
The front panel contains the keypad area and the
LCD area. The rear panel is composed of the stand
Chapter Four Maintenance and Repair
14
and the battery compartment. Open the stand to 90
degrees to set the multimeter on a flat surface. The
battery compartment shall contain 3 AA dry cell
batteries. You can use them for power supply if
necessary.
Chapter Four Maintenance and Repair
15
1.2 Side panel
Fig. 2-2 Side panel
Side panel is shown in Fig. 2-2. The multimeter deploys
universal Micro-USB interfaces for power supply and
Chapter Four Maintenance and Repair
16
charge. The input voltage is 5V. You can find one hook on
each side of the multimeter to fix the shoulder strap for
your convenience.1.3 Top end illustration
The top end has an anti-dust cover to protect the fiber
connector and the output surface from being contaminated
by dust. Taking the top left corner as the axis, the cover
opens towards the left from the right side.
Chapter Four Maintenance and Repair
17
Section Two Operation Instructions
2.1 Default setting
The multimeter contains a built-in rechargeable
battery when it comes out of the factory. Please ensure
the battery is adequate in case it serves as the only
power source. A stabilized DC power adapter is
recommended for the battery charge. Use the
rechargeable battery for supply after it is full. When the
DC power adapter supplies power, the multimeter
performs normally even though the battery is charging.
2.2Optical power measurement
Chapter Four Maintenance and Repair
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2.2.1Turning on and off
Hold down the power switch 1 sec to activate
self-test mode of AV2498Cmultimeter. It will stay in the
following modes after the self-test is accomplished:
1）Range is auto;
2）Measurement mode is in dBm;
3）Wavelength is 1550nm.
Hold down the power switch 1.5 sec to turn it off and
you will see nothing on the screen after power-off.
Chapter Four Maintenance and Repair
19
2.2.2 Zero function
Zero the multimeter prior to measurement of ultralow
optical power(For P1:abosulte optical power at the
wavelength of 850nmis lower than -54dBm， absolute
optical power at other wavelengths is lower than -60dBm；
for P2: absolute optical power at the wavelength of
850nmis lower than -34dBm, absolute optical power at
other wavelengths is lower than -40dBm; zero is
unnecessary for P3). Close the protector of the optical
power input port and press【Zero】. Maintain the range at
the minimum during zero. The multimeter costs approx. 2
Chapter Four Maintenance and Repair
20
sec on zero and it returns back to the measurement mode
afterwards.
2.2.3Optical input
If the input optical fiber has standard FC/PC
connector, it can be inserted directly to the optical power
input interface; in case the input optical fiber has LC, SC
and ST connectors, change the interface of AV2498C
multimeter for convenient operation. Pay special attention
to strength and wavelength of the input light to prevent the
multimeter from being damaged by ultrahigh optical power.
Chapter Four Maintenance and Repair
21
2.2.4Selection of measurement mode
Press【λ】 to choose a wavelength and make it
identical or close to that of the measured light. As response
of photodiode to optical spectrum is not flat, errors may
occur when the wavelength of the measured light is
different (even greatly) from the chosen wavelength.
1）Absolute measurement: press 【dBm/dB/W】 during
measurement based on users’ habits or test features to
generate readings of linearity (W) and logarithm value
(dBm). Test result is linearity when the unit displayed is
mw, µw, nw or pw; and result shows logarithm value if
Chapter Four Maintenance and Repair
22
the unit displayed is dBm.
Logarithm value（dBm）＝10*log（measured linearity
value/1mW）
2）Relative measurement: press 【dBm/dB/W】 to activate
relative measurement (with dB on the screen). Existing
power value is stored in the multimeter as a reference value.
If the input optical power is changed, displayed value is the
discrepancy between the existing value and the logarithm
value reading of the reference value. This mode is
convenient for test of optical power attenuation.
2.2.5Backlight function: Users may have difficult in
Chapter Four Maintenance and Repair
23
reading contents showed on the LCD in dim light, press
to activate the backlight function for your
convenience.
2.2.6Light source function: initial status of the light source
is off. Hold down to enter the mode of light source
setting. Statuses of the light source are: OFF, 1550nm,
1310nm and light source cycle OFF. Hold down the
backlight key to exit this mode. When you activate the
mode of light source setting, the light source status is the
same with the status when this mode is deactivated. The
light sources returns back to the initial status when the
Chapter Four Maintenance and Repair
24
multimeter is turned off.
2.2.7Loss measurement
1) Connect the output port of the light source and the
input port of the optical power with the fiber jumper. Turn
on the light source and preheat it for approx. 30 min.
2）Press【dBm/dB/W】to choose relative measurement
mode, you will see 0.00dB on the screen. Connect device
under test (DUT) to the optical path in series, the value
displayed after the power reading is stabilized is the optical
loss value of the DUT(dB).
Chapter Four Maintenance and Repair
25
2.3 Battery management
2.3.1 Capacity indication
The multimeter comes with a built-in rechargeable
lithium battery. Dry cell batteries serve as a spare power
source. When the multimeter is operating, the internal
monitoring circuit supervises the battery capacity, and the
LCD shows battery level in real-time. Please charge timely
when the capacity becomes empty. Otherwise, the
intelligent battery switching mode will be activated.
2.3.2 Intelligent battery switching
Power supply priority of the multimeter is as follows:
Chapter Four Maintenance and Repair
26
power adapter/portable power—>built-in rechargeable
battery—>dry cell batteries. When the rechargeable battery
is in use, the dry cell batteries won’t work; when the
rechargeable battery capacity is low, the latter will be
activated. The rechargeable battery supply will be
deactivated and the battery level will disappear from the
LCD.
Chapter Four Maintenance and Repair
27
Chapter Three Operating Principles and Technical
Specifications
Sections One Operating Principles
Diagram of operating principles of AV2498Cmultimeter is
shown in Fig. 3-1.
Chapter Four Maintenance and Repair
28
Fig. 3-1 Diagram of operating principles of AV2498Cmultimeter
Chapter Four Maintenance and Repair
29
Section Two Technical Specifications
1. Operating specifications
Operating wavelength: 850nm，1300nm，1310nm，1550nm
Power range of module P1: -70dBm～+3dBm
Power range of module P2: -50dBm～+26dBm
Power range of module P3: -50dBm～+3dBm
Power accuracy of module P1:±0.25dB （ -55dBm ～
+3dBm），
±0.25dB±0.1nW(-70dB
m～-55dBm)
Power accuracy of module P2:±0.25dB （ -35dBm ～
Chapter Four Maintenance and Repair
30
+26dBm），
±0.25dB±10nW(-50dB
m～-35dBm)
Power accuracy of module P3: ±0.25dB
Resolution:0.01/0.001dB
Central wavelength of the light source:
1310±20nm.1550nm±20nm
Optical output power:≥-3dBm
Short-term stability:±0.05dB/15min
2. Environment adaptability
Operating temperature: -10℃～+55℃
Chapter Four Maintenance and Repair
31
Storage temperature: -40℃～+70℃
Operating humidity: 5%～95%RH
Operating power: adapter（input: 100~240V AC, 50～60Hz;
output: DC5V, ≥1A）,
Rechargeable battery (nominal voltage: 3.7V，≥1000mAh）
3 AA alkaline dry cell batteries（not included in the
accessories）
3. Mechanical characteristics:
Max. Dimensions（W×H×D, mm） : 86×186×40
Chapter Four Maintenance and Repair
32
Weight: ≤0.5kg
*Note: technical specifications and test conditions
（temperature:23℃±2℃, humidity: 20%～80% RH）
Chapter Four Maintenance and Repair
33
Chapter Four Maintenance and Repair
1 Matters need attention
Proper usage and maintenance of the multimeter can
preserve the performance and specifications and prolong its
service life.
1.1 Power supply precautions
The power supply sources are built-in rechargeable
batteries, dry cell batteries or an external power adapter.
Micro-USB is the interface type for external power adapter.
Dry cell batteries are also suitable for the multimeter.
Please take them out when the multimeter is not in use for a
Chapter Four Maintenance and Repair
34
long time. The power adapter is recommended if the
multimeter is going to be used for a long time. The batteries
are consumable, not covered by the warranty.
a）Application of rechargeable batteries
1）Do not leave the batteries or the multimeter with the
batteries inside in super hot environments, such as vehicles.
2）Charging and discharging the batteries regularly in
case they are stored over half a year.
3） Do not discharge the batteries fully to avoid
batteries failure.
4）Due to self-discharge and current leakage, the
Chapter Four Maintenance and Repair
35
batteries will become exhausted even though the
multimeter hasn’t been used for a period of time.
b）Low voltage warning
When voltage of the rechargeable batteries is low, the
sign of batteries level in the top right corner of the LCD
will indicate empty power and the multimeter can only
work another 10 min. Please charge the batteries or fill in
dry cell batteries or auto-off of the multimeter will be
activated. When the rechargeable battery is the only
working power source, and the sign indicating battery level
in the top right corner is empty, the battery capacity is
Chapter Four Maintenance and Repair
36
extremely low, the internal voltage is unstable and the
power test is inaccurate. The multimeter can only work
another 20 min (the light source is not activated) before
auto-off. Operation of this multimeter at this time is not
recommended. Please charge the battery or fill in dry cell
batteries timely.
c）Charge the batteries inside the multimeter
The charging circuit inside the multimeter can
perform charging when the power adapter is used. Charging
mode and timing are set up automatically.
1）Check input AC voltage of the power adapter prior to
Chapter Four Maintenance and Repair
37
application.
2）Connect the input of the adapter to AC power.
3）Connect the output of the adapter to the power input,
which will charge the batteries automatically.
1.2 Test precautions
Make sure the connector type of the fiber-optic
jumper and that of the input port of optical power test are
identical, and are connected firmly. The optical fiber end
should be clean before the connection.
1.5 Other precautions
a）Avoid mechanical vibrations, shocks, falling down and
Chapter Four Maintenance and Repair
38
other mechanical damages to the multimeter.
b）Protect the optical transmitting and receiving ends from
being touched by firm and dirty stuff. Use the anti-dust
cover to make them free of dust or erosion by noxious gas
when not in use.
c）Pack up the multimeter before storage and keep it in a
dry room with good ventilation. Put it in the dedicated
shipping container during transportation.
d）Clean the fiber-optic jumper surface with absorbent
cotton and anhydrous alcohol.
2 Repair
Chapter Four Maintenance and Repair
39
AV2498C Optical Multimeter is a precise
photoelectric integrated instrument, repair and calibration
of which are complicated.
a）Return it back to the factory for repair when it encounters
breakdowns;
b）In case test value deviates a lot or output power value of
the light source is comparatively low, please check if the
input and output ports are contaminated. If so, clean them
with absorbent cotton and anhydrous alcohol. The
calibration cycle is one year. Common breakdowns and
troubleshooting are listed in Table 4-1.
Chapter Four Maintenance and Repair
40
Table 4-1 Common breakdowns and troubleshooting
No.
Breakdowns
Reasons
Troubleshooting
1
Find no USB
devices.
USB drives are
not correctly
installed.
Reinstall USB drives
correctly.
2
USB devices
cannot be
recognized.
USB drives are
not correctly
installed.
Reinstall USB drives
correctly.
3
Tested
optical
power is
abnormal.
1） Skip the
step of zero
before test；
2） The optical
1） Perform zero in a
light-free condition;
2） Replace the
optical fiber or
clean the
Chapter Four Maintenance and Repair
41
fiber is
broken or the
connectors
are
contaminated
.
connectors.
3 Warranty
The AV2498C multimeter enjoys 18 months warranty.
We offer free repair or replacement for any multimeters
defective in quality with the premise that transportation,
storage and operation instructions are complied with.
Chapter Four Maintenance and Repair
42
For storage of the multimeter, pack it up properly and
store it in a dry room with good ventilation at an ambient
temperature of -40℃~+70℃. Place it in a dedicated
shipping container to avoid severe shocks during
transportation.
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