[1] Operating Precautions•••••

Do not stare directly at the laser light or allow its reflections
enter your eyes during measurement. Laser light incident toyour eyes may lead to degradation or loss of eyesight. Special
care is required for the IV light which is invisible for naked eyes.
An excessive optical input may damage the photodiode inthe light sensor. Do not apply light that is stronger than themeasurable range (40 mW).
Be careful not to damage the light sensor surface or stain itby douching with a bare hand. Scratches or stain maydeteriorate the sensitivity of the instrument. If the lightsensor surface gets dirty, wipe lightly with ethyl alcohol.
This instrument incorporates the auto power save function, whichturns it off in 30 minutes after an operation. To turn the instrument
on after it has been turned off by the auto power save function, set
the Power/Range 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.

[2] Applications

This instrument is a pocket-sized laser power meter featuring
excellent portability and operability.
It can be applied easily in check and maintenance of the
optical power levels of equipment using laser light.
Using 633 nm of a He-Ne laser as the reference wavelength,
this instrument enables direct reading of the optical power ofvisible-range laser light from a visible laser pointer, DVDplayer’s optical pickup, etc.
The power of other wavelength can also be measured byconverting the reading according to the spectral sensitivity
characteristic table (typical values).

Dempa Bldg., 4-4 Sotokanda 2-Chome
Chiyoda-ku, Tokyo, Japan

INSTRUCTION MANUAL[6] Measurement

How to open or close theprotective cover
1. To open the protective cover,push and hold the button on theleft side of main body into thedirection shown in the figure,and open the protective cover.
2. To close the protective cover, first store the light sensor
probe in the storage position of the main body as described
below, and then close the protective cover until it is locked.
How to store the light sensor probe
The light sensor probe can be stored in the main body asshown below.
1. Fit the light sensor probe
into the storage position sothat the light sensor surface
faces up.
2. Bend the cord and store itin the space on the right of
the light sensor probe.

-4-Notes)••••

How to correct the wavelength sensitivity of the light sensor
The reference wavelength that can be read directly with this
instrument is 633 nm. To measure light with wavelengths
other than 633 nm, convert the reading using the sensitivity
correction coefficient obtained from the photodiode’s spectral
sensitivity characteristics (typical values).

-5-• 3999 full-scale count with a bar graph display.
• Direct reading of the laser power of the reference•

body for measurement.

wavelength of 633 nm, while the laser power of otherwavelengths can be read by converting it according to thespectral sensitivity characteristic table.
• Wide measuring range from 0.01 μW to 39.99 mW.
• MIN/MAX hold functions.
• Auto power save function prevents wasting of battery power.

[4] Nomenclature
LCD display panel

Wavelength (nm)400442450488
500
515
550
600

150

Correction
coefficientX 10.4
X 3.86
X 3.29X 2.08
X 1.93X 1.71X 1.39X 1.12

Correction
coefficient

Wavelength (nm)Wavelength (nm)

X 1.00X 0.95
X 0.90X 0.84
X 0.77
X 0.73
X 0.72
X 0.70

633
650
670
700
750
780
800
830

850
900
940
950
1000
1050
1060
1100

Correction
coefficient

X 0.69X 0.68
X 0.72
X 0.74
X 0.96X 2.25X 2.70X 5.40Spectral sensitivity characteristic (representing value)

140
130
120
110

100
90
80
70
60
50
403020100400 450

500

550

600

650
633

700

750

800

850

Wavelengthλ(nm)900950 1000 1050Example)
When the measured laser light wavelength is 780 nm and thepower meter reading is 2.44 mW:
Reading Correction coefficient Wavelength-converted value
2.44 (mW) x 0.73≒1.78 (mW)
-6-switch• Power/Range
This rotary switch is used to turn the illuminance meter•

on-off and switch the measurement range to the 40 μW, 400μW, 4 mW or 40 mW range.
Battery warning indicator
When the internal batteries are nearly exhausted and thesupply voltage drops, blinking “BT” appears in the display. If
this happens, please replace both batteries with new ones.
MIN/MAX Hold button (Also used as the protection cover lock)Push this button during measurement to set the digital value
display to the MIN Hold or MAX Hold mode as shown below.
Normal measurement

Light sensor probe
storage position

Protective coverPush
MIN Hold

The meter uses 633nm of He-Ne laser reference wavelength.
Using the below conversion table of spectral sensitivity
characteristic (representing value), measurement of wavelengths
from 400nm to 1100nm can be made as rough readings.
Conversion readings (W) = reading (W) x correction coefficient
Correction
Wavelength(nm) coefficient

×10.4×3.86
×3.29
×2.08
×1.93
×1.71
×1.39
×1.12

400
442
450
488
500
515
550
600

MIX/MAX
Holdbutton

Correction
Wavelength(nm) coefficient

633
650
670
700
750
780
800
830

×1.00
×0.95
×0.90
×0.84
×0.77
×0.73
×0.72
×0.70

Correction
Wavelength(nm) coefficient

850
900
940
950
1000
1050
1060
1100

×0.69
×0.68
×0.72
×0.74
×0.96
×2.25
×2.70
×5.40

Spectral sensitivity characteristic (representing value)

150
140130120
110
100
9080
70
6050403020100400 450500

550600650 700 750 800 850 900633
Wavelengthλ(nm)950 1000 1050 1100

Power/Rangeswitch
Light sensor window

Conversion readings (W) = reading (W) x correction coefficient

auto power save function of the instrument turns• The
it off in 30 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.
When over range, "4000" displays with "4" in thehighest digit blinking.
Laser should be received on the center of the sensor atright angle.
With certain lasers, the laser power may vary due to“return light” from the light sensor surface. In this case,change the angle of the light sensor surface so that thereflected light does not return directly to the laser lightoutlet.
Measurement of weak laser power (below 1 mW) tends
to be affected by ambient light (disturbance). In thiscase, it is required to take a countermeasure against
disturbance, by performing measurement in a dark room.

[5] Functions-1-

Relative sensitivity (%)

How to integrate the light sensor
probe with the main body formeasurement
Insert the light sensor probe in
the position on the top left of themain body as shown in thefigure.

Measurement Procedure
1. Set the measuring range to the maximum range (40 mW).
2. Apply the laser beam to the light sensor surface.
3. After measuring the current power, set the measuring range
to the optimum range.
4. After completing measurement, set the Power/Range switch to OFF.

[3] Features• Pocket size.
• Separate light sensor probe can be integrated with the main

Relative sensitivity (%)

Thank you for purchasing SANWA laser power meter LP1.
Read this manual carefully before use for safe use of the instrument.
Retain this manual together with the instrument for future reference.

-2-

Light sensor probe[7] Maintenance and Administration

To maintain accuracy, perform calibration and inspection at least once an 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 surface is damaged.
• Check if the light sensor cord is damaged.
If any of the above parts is damaged, do not use the instrument
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 screwdriver.
2 Remove the battery compartment cover and take out theexhausted batteries.
3 Insert new batteries without mistaking the + and – polarity.
4 Attach the battery compartment cover and clamp it with the screw.
4. Storage
The panel and case are little resistant to volatile solutions and heat. Donot wipe the thermometer 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 place which it may drop.
Do not store the instrument under direct sunlight or in aplace with low temperatures, high humidity or condensation.
Be sure to remove the batteries when the instrument is not
to be used for an extended period.

••••[8] After-Sale Servicing

For information of repair, please contact the dealer, selling
agent or maker.
-7-• MIN Hold mode:

Push
Push

MAX Hold

Holds the minimum value during measurement anddisplays it in the digital display. Indicated by “DH” and“MIN” shown in the display.
• MAX Hold mode:
Holds the maximum value during measurement anddisplays it in the digital display. Indicated by “DH” and“MIN” shown in the display.
Using the MAX Hold function makes it possible display
always the maximum value measured. This solves theproblem in the meter reading, that varies depending on theposition, distance and angle of the incidence of laser beam
into the light sensor surface.

Notes) • The bar graph display is not held.
• The MIN/MAX Hold mode is canceled when themeasurement range is changed.
-3-[9] Specifications
Light sensor element Si photodiode (Light sensor surface diameter Ø 9 mm)
Measurable wavelength 400 nm to 1100 nm
range
Directly-readable 633 nm (He-Ne laser)
wavelength
Other wavelengths should be converted using typicalcorrection coefficient
Display
Digital display: 3999 full scale
Bar graph display: 42-segment display“Over” display“4000” with “4” in the highest digit blinking
Low battery indication Blinking “BT” appears in the display when the built-in batteries
are nearly exhausted and battery supply voltage drops
Sampling rate
Digital display: Approx. 2 times/sec.
Bar graph display: Approx. 20 times/sec.
Measuring ranges 40 μW range: 0.01 μW to 39.99 μW
400 μW range: 0.1 μW to 399.9 μW
4 mW range: 0.001 mW to 3.999 mW
40 mW range: 0.01 mW to 39.99 mW
Measuring accuracy ±5 % (in the 4 mW range, at the reference wavelength of633 nm and 1 mW)
Temperature: 23 ℃ ±2 ℃
Functions
MIN Hold function, MAX Hold function
Auto power save function (30 min. after operation)
EMC directive, RoHS directive IEC61326(EMC). EN50581(RoHS).
Power supply
LR-44, x 2
Power consumption Approx. 6 mW
Environmental condition Altitude 2000 m or below, pollution degree Ⅱ.
Operating temperature Temperature 0 to 40 ℃, humidity 80 %RH or less/humidity range(without condensation)
Storage temperature Temperature -10 to +50 ℃, humidity 80 %RH or less/humidity range(without condensation)
Main body dimensions 117(H) x 76(W) x 18(D) mm, approx. 120 grams& massLight sensor probe 84(H) x 16(W) x 10(D) mm
Sensor cord length Approx. 0.5 m when extended
Provided accessories Instruction manual x 1

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