Thank you for purchasing SANWA illuminance meter LX20.
Read this manual carefully before using the instrument forsafety use. Retain this manual together with the instrument
for future reference.
[1] Operating Precautions
Be careful not to stain or damage the light sensor window.
If the light sensor window gets dirty, wipe lightly with asoft, dry cloth.
Do not move the light sensor probe cord during
measurement, as this may result in variation of thedisplayed value. Take special care not to move the cord
particularly during measuring low illuminance values.
This instrument incorporates the auto power savefunction, which turns it off in 15 minutes after anoperation. To turn the instrument on after it has been
turned off by the auto power save function, set theRange switch to OFF and keep it in the OFF position for
more than 1 second before setting it to another position.
Be sure to set the Power/Range switch to OFF after use.

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LX20

ILLUMINANCE METER
Dempa Bldg, Sotokanda 2-Chome,Chiyoda-ku, Tokyo, JapanTEL.: 81-3-3251-0941 FAX.: 81-3-3256-9740
Web site: www.sanwa-meter.co.jp
e-mail: exp_sales@sanwa-meter.co.jp

INSTRUCTION MANUALHow to store the light sensor probe
The light sensor probe can be stored in the main body as shown below.
1. Fit the light sensor probe into the storage position so that the lightsensor window faces up.
2. Bend the cord and store it in the space on the right of the light sensorprobe.

3) Insert a new battery without
mistaking the + and - polarity.
4) Attach the battery compartment
cover and clamp it with the screw.
The button-battery is madeof oxidized silver, etc.
Please keep it away fromlittle children lest they should swallow it in.
CAUTION
Set a battery with its polarities facing in the correct directions.

[7] Maintenance and Administration

To maintain accuracy, perform calibration and inspection
at least once a year.
1. Maintenance check1) External finish• Check if the external finish is damaged by dropping theinstrument, etc.
2) Light sensor• Check if the light sensor window is damaged.
• Check if the light sensor cord is damaged.
If any of the above parts is damaged, do not use theinstrument but have it repaired.
2. Calibration
For calibration and inspection of the instrument, pleasecontact dealer, sole agent and maker.
3. Battery replacement
Replacement Procedure:
1) Remove the screw retaining the battery compartment
cover using a Phillips screwdriver.
2) Remove the battery compartment cover and take out
the exhausted battery.
-5-

Batteris when the meter is shipped:
A battery for monitoring has been installed prior to shipment from the factory.
It may be discharged before the expiration of the described battery life.
*The battery for monitoring is a battery used to check the functions andperformance of the product.

4. Storage
The panel and case are little resistant to volatile solutions and heat. Donot wipe the instrument using lacquer thinner or alcohol and do notplace it heat a source of high temperatures (soldering iron, for example).
Do not store the instrument in a place subject to vibrations or in a placefrom it may drop.
Do not store the instrument under direct sunlight or in a place with low
temperatures, high humidity or condensation.
Be sure to remove the battery when the instrument is not to be used foran extended period.

••••[8] AFTER-SALE SERVICE

1.Warranty and Provision
Sanwa offers comprehensive warranty services to its end-users and to its
product resellers. Under Sanwa's general warranty policy, each instrument iswarranted to be free from defects in workmanship or material under normal use
for the period of one (1) year from the date of purchase.
This warranty policy is valid within the country of purchase only, and applied only
-6-[2] Applications
This instrument is a pocket-sized illuminance meterfeaturing excellent portability and operability.
It can be applied easily to a wide range of purposes
from brightness checking in daily life to illumination
maintenance in offices and factories as well as
illumination management in agriculture and forestry.
[3] Features• Easy-to-carry pocket size.
• Separate, stick-shaped light sensor (window diameter 9mm) from the main body enables measurement of anarrow position or area. The light sensor can also be
integrated with the main body for measurement.
• 4039 full-scale count with a bar graph display.

• Improved measurement accuracy by using a siliconphotodiode, which has a spectral sensitivity approximating
the relative luminous efficiency specified by CIE (Commission
Internationale d'Eclairage), in the light sensor.
• Wide measuring range of 0.1 lx to 403.9 klx (403,900 lx).
• Data hold function.
• Auto power save function prevents wasting of battery power.
[4] NomenclatureLight sensor probe
storage position

Protective cover

warning indicator• Battery
When the internal battery is nearly exhausted and thesupply voltage drops, blinking “BT” appears in the display. Ifhappens, please replace the battery with new one.
• thisData Hold button (Also used as the protection cover lock)•Light source
Mainbody

Push this button during measurement to hold the digitalcurrent value and bar graph display. “DH” appears in
the display while the display data is held. Pushing thisbutton again releases the data hold function and causes“DH” to disappear from thedisplay.

Light sensor
probe

It is also possible to measure illuminance while the light sensor probe
is integrated with the main body.
Light source

How to integrate the light sensor probewith the main body for measurementInsert the light sensor probe in theposition on the top left of the main bodyas shown in the figure on the right.

LCD
displaypanel
Data
Holdbutton

Power/Rangeswitch
Light sensor window

Light sensor probe

Mainbody

How to open or close the protective cover
1. To open the protective cover, pushand hold the button on the left sideof main body into the direction
shown in the figure, and open theprotective cover.
2. To close the protective cover, first
store the light sensor probe in thestorage position of the main bodyand then close the protective coveruntil it is locked.

Light sensor
probe

3. After completing measurement, set the Power/Range switch to OFF.
Notes) When over range, displays “OL”.
The illuminance reference plane is located at thetop of the sensor as shown below illustration.

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Illuminance reference plane

Light sensor
windowswitch• Power/Range
This rotary switch is used to turn the illuminance meter

on-off and switch the measurement range to the 400 lx,
4000 lx, 40 klx or 400 klx range.

[6] Measurement
Measurement Procedure
1. Set the measuring range according to the illuminance to be measured.
2. Extend the light sensor probe cord to the point you want tomeasure illuminance and point the light sensor window toward themeasurement target light source.

Notes) The auto power save function of the instrument turns it
off in 15 minutes after an operation. To turn theinstrument on after it has been turned off by the auto
power save function, set the Range switch to OFF andkeep it in the OFF position for more than 1 second before
setting it to another position.

-1--2--3--4-

to the product purchased from Sanwa authorized agent or distributor.
Sanwa reserves the right to inspect all warranty claims to determine the extent towhich the warranty policy shall apply. This warranty shall not apply todisposables batteries, or any product or parts, which have been subject to one of
the following causes:
1.A failure due to improper handling or use that deviates from the instruction manual.
2.A failure due to inadequate repair or modification by people other than Sanwa
service personnel.
3.A failure due to causes not attributable to this product such as fire, flood andother natural disaster.
4.Non-operation due to a discharged battery.
5.A failure or damage due to transportation, relocation or dropping after the purchase.
2.Repair
Customers are asked to provide the following information when requesting services:
1.Customer name, address, and contact information
2.Description of problem
3.Description of product configuration
4.Model Number
5.Product Serial Number
6.Proof of Date-of-Purchase
7.Where you purchased the productPlease contact Sanwa authorized agent / distributor / service provider, listed in
our wbsite, in your country with above information.An instrument sent to Sanwa /agent / distributor without those information will be returned to the customer.
Note:1)Prior to requesting repair,please check the following:
Capacity of the built-in battery, polarity of installation.
2)Repair during the warranty period:
The failed meter will be repaired in accordance with the conditions
stipulated in 1.Warranty and Provision.
3)Repair after the warranty period has expired:
In some cases, repair and transportation cost may become higher than theprice of the product. Please contact Sanwa authorized agent / service provider
in advance.
The minimum retention period of service functional parts is 6 years after thediscontinuation of manufacture. This retention period is the repair warranty
period. Please note, however, if such functional parts become unavailable forreasons of discontinuation of manufacture, etc., the retention period may
become shorter accordingly.

4)Precautions when sending the product to be repaired:
To ensure the safety of the product during transportation, place the product in a
box that is larger than the product 5 times or more in volume and fill cushion
materials fully and then clearly mark ”Repair Product Enclosed” on the box surface.
The cost of sending and returning the product shall be borne by the customer.
3.SANWA web site
http://www.sanwa-meter.co.jp E-mail: exp_sales@sanwa-meter.co.jp-7-[5] Functions[9] Specifications
Light sensor element
Display

Si photodiode with approximated relative luminous efficiency
Digital display: 4039 full scale
Bar graph display: 41-segment display“Over” display
displays“OL”
Battery warning display Blinking “BT” appears in the display when the built-in battery
is nearly exhausted and battery supply voltage drops
Digital display: Approx. 2 times/sec
Sampling rate
Bar graph display: Approx. 20 times/sec
Measuring ranges
400 lx range: 0.1 lx to 403.9 lx
4000 lx range: 1 lx to 4039 lx
40 klx range: 0.01 klx to 40.39 klx
400 klx range: 0.1 klx to 403.9 klx±(5 % of reading + 1 digit) at 3000 lx or less, ±(7.5 % of reading
Measuring accuracy+ 1 digit) at 3000 lx or more. (Equivalent to JIS General Class
A for products for use other than certification and trading)Temperature: 23 ℃±2 ℃±5 % at 23 ℃ within operating temperature range
Temperature drift
Relative spectral sensitivity Approximating the standard luminous efficiency
Functions
Data Hold function
Auto power save function (15 min. after operation)
EMC directive, RoHS directive IEC61326(EMC). EN50581(RoHS).
Power supply
LR44 1.5 V x 2Power consumption
Approx. 13 mW
Environmental condition Altitude 2000 m or below, pollution degree Ⅱ.
OperatingTemperature 0 to 40 ℃, Humidity 80 %RH or lesstemperature/humidity range (without condensation)
Storage
Temperature -10 to +50 ℃, Humidity 80 %RH or
temperature/humidity range less (without condensation)
Main body dimensions & mass 117(H) x 76(W ) x 18(D) mm, approx. 120 grams
Light sensor probe
84(H) x 16(W ) x 10(D) mm
Sensor cord length
Approx. 0.9 m
Provided accessories
Instruction manual x 1

Design and specifications are subject to change for reasons of improvement, etc.
-8-

Illuminance
TypeReference: Illuminance Standard in JIS Z 9110
1500700300* Study,* reading (long hours or
small letters), sewing

Housing* Sewing (darkmaterials)

Schools* Precision drafting,Drafting room,* blackboard surface,* sewing machine,* precision experiments * library reading room,* sewing,* precision handicraft* Designing, * drafting, Office, drafting room,* typing, * calculation, telephone exchange room,
power distribution panel,* key punching
instrument meter panel

Offices150* Reading, *Makeup, Living room, childrenrooms, drawing room,* Dining
dining room, kitchen
General classrooms, Auditorium, meeting
special classrooms, rooms, corridors,
library reading room, staircases
gymnasium

Theaters

Operating * Biopsy,
table:* emergency treatment,
10,000* medicine preparation
or moreOperating room, emergency
treatment room, visual examination,
medicine preparation,* technical lab, * injection

30

Consultation rooms,
examination rooms,
dispensary, waitingrooms, medical offices

Emergency
staircases

70 - 15: 15 - 3:
Expressway tunnels(The illuminance of theTunnels High-traffic roads
tunnel entrances should
be higher than this level.)Pre-consultation rooms,
general hospital rooms,
X-ray rooms, medicine
warehouse* Ticket counter,entrances,
staircases

Projection booth,
corridors, staircases

Hotels

Accounting office

Reception desk,
restaurants

Guestrooms, entertainment
room, corridors, lobby

Restaurants* Sample cases

Guestrooms, waiting
rooms and passages

Beautyparlors andbarbers* Hairdressing,* hair setting, * makeup* Cash register,
cooking room,* tables* Haircutting,* dressing

Shops* Highlighting in store shelves,* Highlighting in show
windows,* Show windows,* Spotlighting in showcases general showcases

General exhibitions,general lighting

Department
stores* Show windows, ground General exhibition,
floor decorations,general showcases* Important showcases

Exhibitions withambience

15 lx

Entrance, staircases,
corridors, emergency
staircases, garage

Director rooms,
Workshops, locker rooms, Emergency
conference rooms, staircases, warehouses
staircases
reception rooms,
entrance, elevators

Roads
and parks
Hospitals

70

Audience rooms(during intermission),emergency staircases,
garden1.5 - 0.3:
Low-traffic roads, roads,
parks and open spaces
in residential areas

3 - 1.5 Audiencerooms(during shows)

General lighting*: The specified illuminance can be obtained by combining local illuminations. In this case, it is still desirable that the general illumination illuminance is morethan 1/10 of the illuminance achieved using the local illumination.

DRAWING No.LX20 01-1906 2040 6017