PCE Instruments PCE-LMD 100 Users guide

CONTROL UNIT

FOR OPTICAL RADIATION MEASUREMENT PROBES

PCE-LMD 100 and PCE-LMD 200

Instr

uction manual

2

TABLE OF CONTENTS

1. CHARACTERISTICS OF INSTRUMENT...........................................................................................4

1.1. Equipment ...................................................................................................................................4

1.1.1. Basic accessories:................................................................................................................4

1.1.2. Input and output connectors of control unit .............................................................. 5

1.2. Technical data........................................................................................................................... 5

2. CONTROL OF INSTRUMENT...........................................................................................................5

2.1. Control keys ................................................................................................................................ 5

2.2. Menu .............................................................................................................................................6

2.2.1. Zeroing ..................................................................................................................................6

2.2.2. Memory ................................................................................................................................. 6

2.2.3. Measurement setup...........................................................................................................6

2.2.4. User setup.............................................................................................................................7

2.2.5. Calibration ............................................................................................................................7

2.2.6. Applications..........................................................................................................................7

2.2.7. Panel info..............................................................................................................................7

2.2.8. Head info...............................................................................................................................7

2.3. Splash screen ..............................................................................................................................7

2.4. Results screen.............................................................................................................................8

2.4.1. Active control keys. ............................................................................................................8

2.4.2. Measurement window.......................................................................................................9

2.4.3. Measurement results format...........................................................................................9

2.4.4. Icon bar................................................................................................................................10

2.4.5. Date and time ....................................................................................................................10

3. WORKING WITH MEASUREMENT PROBE.................................................................................10

3.1. Connection of measurement probe....................................................................................10

3.1.1. Elements of measurement system...............................................................................10

3.1.2. Assembling of measurement system...........................................................................11

3.2. Measurement............................................................................................................................11

3.2.1. Preparation for instrument operation ........................................................................11

3.2.1.1. Zeroing of detector ...........................................................................................11

3.2.1.2. Zeroing of measurement system ...................................................................11

3.2.1.3. Automatic change of measurement range..................................................11

3.2.1.4. Additional actions ..............................................................................................11

3.2.2. Measurement triggering.................................................................................................11

3.2.3. Averaging of results.........................................................................................................12

3.2.4. Temperature compensation ..........................................................................................12

3.2.5. Luminance mode...............................................................................................................12

3.3. Calibration of measuring probe...........................................................................................12

3.4. Relative measurement ...........................................................................................................13

3.5. Integration.................................................................................................................................14

3.6. Statistics.....................................................................................................................................14

3.7. Measurements memory .........................................................................................................15

3.7.1. File name and format.......................................................................................................15

3.7.1.1. Absolute measurement ....................................................................................15

3.7.1.2. Relative measurement......................................................................................15

3.7.1.3. Integration ...........................................................................................................15

3.7.1.4. Statistics ...............................................................................................................16

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3.8. Connection of instrument to PC ..........................................................................................16

4. APPLICATIONS.................................................................................................................................16

4.1. Medical monitors .....................................................................................................................16

4.1.1. Operation of application.................................................................................................17

4.1.2. Conduction of tests..........................................................................................................17

4.1.3. Data file...............................................................................................................................18

5. USAGE RECOMMENDATIONS......................................................................................................18

5.1. Internal battery ........................................................................................................................18

5.2

. Repairs and maintenance.......................................................................................................19

6. CE MARKING AND WEEE DIRECTIVE..........................................................................................19

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1 . CHARACTERISTICS OF INSTRUMENT

measurement probe

charging status

The control unit is designed to control measurement probes used for optical radiation
measurement. The measurement probes are complete meters that communicate with a
control unit through a digital interface with the use of the manufacturer’s data
transmission protocol. With the aid of the control unit you can read measurement
results, average them and save them to the memory afterwards. You can also change
the settings of the attached probe and calibrate it. The instrument is equipped
with a micro SD card, on which the measurements results can be saved. The data on
the micro SD card can be transmitted to a PC with the use of a standard memory card
reader. You can also connect the unit with a PC using a micro USB cable, so in this case
the card is seen as an external drive. The control unit is equipped with an inbuilt high­capacity LiION battery that can be charged with the fast charger which is an accessory to
the instrument or with any other charger used for mobile phones with a micro USB
connector.

socket

U

SB socket

LED

Fig. 1.1. control unit – main view.

exte

SD card slot

1.1. Equipment

1.1.1. Basic accessories:

• Mains charger.

• 1m USB (micro USBA-USBB)

• 4GB memory card.

• Plastic carrying case used for transport of instruments.

• Instruction manual.

cable.

nsion socket

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1.2.2 Input and output connectors ofcontrol unit

The instrument is equipped with the below-given elements:

• a FISHER connector that is used to connect the measurement probe to the
instrument,

• a type B micro USB connector used for charging the battery and exchanging data,

• a RJ-11 connector to connect extensions and to the firmware update,

• a micro SD card slot.

The position of input and output connectors is shown in Fig. 1.1.

1.3. Technical data

• Dimensions (excluding a FISHER connector) 107 x 70 x 20mm

• Weight 150g

• Power supply

- internal battery Li-ION 3.6V / 1500mAh

- charger TC21U2 5V / 2.1A

• Environmental conditions:

- temperature -20°C – +50°C

- humidity < 90% (non-condensing)

• Time of continuous operation with a
fully-charged battery 23h

2. CONTROL OF INSTRUMENT

The control of the instrument is possible with the use of the keyboard.

2.1. Control keys

The keyboard of the instrument consists of:

• on/off key:

ntrol keys:

• co

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In order to switch the instrument on, press the following key: . In order to switch
the instrument off, press the same key and hold it down for 3 seconds.

To display the MENU, press the following key on the results screen (see Sec. 2.4). It
is possible to enter the menu only then when the measurement procedure is stopped.

To navigate through the menu, use the following keys:

numerical values, use the given keys: . The following key is
used to save to a file the measured quantity that is displayed on the results screen
(detailed description of measurement memory can be found in Sec. 3.7). When the

results screen is displayed, the key can be used to trigger a single measurement or
to start / stop a continuous measurement.

. To enter

2.2. Menu

2.2.1. Zeroing

Detector – starts the procedure for determination of detector dark current. The

procedure should be conducted only when the probe is covered.

System – starts the procedure for determination of measurement circuit offset voltage.

2.2.2. Memory

New file – creates a new file used for saving data.
Autosave – turns on/off the automatic saving of measurements to the memory.
Interval – sets the time interval between the subsequent auto saves.
Memory card – displays information about the installed memory card: a card type, file

system, capacity and the remaining free space.

2.2.3. Measurement setup

Single – chooses a single measurement mode.
Continuous – chooses a continuous measurement mode.
Relative – chooses a relative measurement mode. When it is turned on, it is necessary to

enter the reference value (the default value is the latest measured value). When the
relative measurement mode is turned on, the statistics and integration are turned off.
Statistics – it is a sub-menu to change the statistics settings. The statistics option is
related solely to both single and continuous measurement modes. As for the integration
mode, the statistical calculations are done independently.
Statistics->Add measurement – adds the last measurement to statistics. If the statistics
is turned off, it turns it on.

Statistics->Clear all – deletes and turns off the statistics.
Statistics->Auto add – turns on/off the function of the automatic adding of every

measurement to statistics.
Integration – turns on/off the integration. If the statistics is turned on, it turns it off. If
the relative measurement is on, it is turned off. Additionally, the autorange and
continuous measurement mode are set; these settings can not be changed in the
integration mode.
Delete integral – it is used to delete the integration results and statistics related to
integration; it requires further confirmation.

Autorange – turns on/off the automatic change of the measurement range.
Averaging – sets the result averaging time.

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Luminance – it is a sub-menu to choose a luminance measurement adapter (only when
the measurement probe is equipped with that function). This option is inactive in the
case of a luminance meter.

2.2.4. User setup

Contrast – adjusts the display contrast.
Brightness – adjusts the brightness of the display.
Backlight – sets the operation mode of display backlight. There are three options to

choose from:

On – the backlight is turned on all the time,
Off – the backlight is turned off all the time,
Auto – the backlight is turned on when any key is pressed and it is turned off when

the set time limit passes.
Autooff – turns on/off the function of the automatic turning off of the instrument. If
the function is activated, the instrument is turned off automatically after the set time of
inactivity (the instrument is not turned off when the measurement runs).

Date and time – enters the current date and time.
Language – selects one of the languages of the menu.

2.2.5. Calibration

This option of the menu triggers the calibration and adjustment procedure described in
Sec. 3.3.

2.2.6. Applications

This sub-menu allows you to run the advanced applications described in Sec. 4.

2.2.7. Panel info

The panel information screen shows: its type, serial number, manufacture year, firmware
version, measurement module version and current battery voltage.

2.2.8. Head info

The information is displayed about the attached measurement probe showing: its type,
serial number, manufacture year, firmware version and calibration factor.

2.3. Splash screen

On the splash screen there is the following data: an instrument name, firmware version
and measurement module version. There is also the manufacturer’s data.

Pressing on the splash screen the following key

ommand referred to as User setup->Contrast. This shortcut is used to set the contrast

c
even if there is no information shown as a result of contrast setting being too high or
too low. Pressing any key leads to entering the results screen. The results screen
displays automatically in 30 seconds’ time.

or causes the display of menu

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2.4 Results screen

Results screen comprises a measurement window, icon bar and a field with the current
date and time. Its layout is different for every operation mode. In the below-given
pictures there is the layout of results screen shown for different operation modes. The
layout is refreshed every second.

Fig. 2.2. Single measurement. Fig. 2.3. Single relative measurement.

Fig. 2.4. Continuous measurement, statistics.

Fig. 2.5. Continuous measurement, integration.

2.4.1. Active control keys.

It enters the instrument menu. It works only when the measurement is
stopped.

It starts/stops a continuous measurement, triggers a single measurement.
It changes the measurement range to a higher level (if the autorange is turned

off, the change of the measurement range is possible only when the
measurement is stopped).
It changes the measurement range to a lower level (if the autorange is turned
off, the change of the measurement range is possible only when the
measurement is stopped).

I

t saves the current measurement to a file.

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2.4.2. Measurement window

The measurement window comprises:

● measurement status indicator:

pause,
measurement,

●

● measured quantity indicator:

indicator of measurement range exceedance,

illuminance/irradiance,
luminance/radiance,
luminous/radiant exposure,
luminance/radiance dose,

● results field with the measured value,

● field of the measured value unit.

Additionally:
for relative measurement mode: the currently measured value in the top left corner of

the screen and the reference value in the bottom left
corner of the screen,

integration mode: the currently measured value in the bottom left corner

of the screen and integration time in the top right
corner of the screen according to the format of
hours:minutes:seconds.

integration and statistics mode: the statistics field comprises: the number of

measurements (n), the minimum value (min), the
maximum value (max), the average value (avr), the
quotient of the minimum and average value (mn/a), the

quotient of the minimum and maximum value (mn/x).
The metric prefix can be added to the original unit of the measured quantity in
accordance with the International System of Units (SI).
The used symbols are given below:

sub-multiplies multiplies

symbol name base 10 symbol name base 10

y yocto 10

z zepto 10

a atto 10

f femto 10

p piko 10

n nano 10

µ

mikro 10

m mili 10

–24

–21

–18

–15

–12

–9

–6

–3

k kilo 10

M mega 10

G giga 10

T tera 10

P peta 10

E eksa 10

Z zetta 10

Y yotta 10

3

6

9

12

15

18

21

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2.4.3. Measurement results format

The measurement result that is read from the probe is displayed on the result field of
the measurement window with the resolution dependable on the type of the attached
probe (in the case of most probes there are 4 significant digits). The position of the
decimal point and multiplier of the unit are matched together in order to achieve the
highest precision.

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2.

4.4. Icon bar

In the bottom of the screen there is an icon bar, which indicates the status of the
instrument:

●

● m

easurement mode:

ode of measurement range change

● m

● time of result average (in seconds),

● exceedance of acceptable operation temperature ran

● memory saving status:

currently chosen measurement range,

single measurement,
continuous measurement,
single relative measurement,
continuous relative measurement,
integration,

automatic,
manual,

probe or temperature sensor failure,

autosave is turned on (with set time interval),
successful data saving to memory (animation),
unsuccessful data saving to memory (animation),

ge of attached

● automatic adding of all measurements to statistics is turned on,
tate of battery:

● s

battery charged to 100%,
battery charged to 80%,
battery charged to 60%,
battery charged to 40%,
battery charged to 20%,
dead battery,

dead battery, it is possible that the instrument
battery is being charged,

2.4.5. Date and time

In the bottom right corner of the screen there is the current date in the format of day,
month, year and the current time in 24 hours format.

turns off automatically

3. WORKING WITH MEASUREMENT PROBE

3.1. Connection of measurement probe

3.1.1. Elements of measurement system

● measurement probe,

measurement module of control unit

●

● control unit

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3.1.2. Assembling of measurement system

The measurement probe should be attached to the socket in the control unit. After
turning on the power supply of the unit there is a splash screen with the information on
the installed firmware and measurement module version.

3.2. Measurement

3.2.1. Preparation for instrument operation

The measurement should be started (see Sec. 3.2.2) and the instrument readings should
be checked with the covered probe. If the instrument does not read zero, the zeroing
procedure should be conducted (see Sec. 3.2.1.1). After the zeroing procedure is
finished, the probe should be uncovered. The instrument is ready for operation.

3.2.1.1. Zeroing of detector

The zeroing procedure of the detector consists in the measurement of the dark current
of the measurement probe detector and its corresponding temperature (see Sec. 3.2.4).
On the basis of this, the probe calculates the correction for the current operation
temperature and deducts it from the result. The proper procedure is started with the
use of the Zeroing->Detector menu command. It can be conducted only with covered
the reception field of the probe. The value of the dark current and the temperature of
the zeroing are saved to the memory of the measurement probe.

3.2.1.2. Zeroing of measurement system

The zeroing procedure of the measurement system consists in the direct measurement
of the correction that results from the measuring circuit offset voltage (see Sec. 3.2.4),
which is deducted from the result. It is automatically conducted after the probe is
connected to the control unit and whenever the detector is zeroed. The User can start
the procedure of the measurement system zeroing by using the Zeroing->System menu
command. The value of the correction and the temperature of the zeroing are saved to
the memory of the probe.

3.2.1.3. Automatic change of measurement range

In order to turn on/off the automatic change of the measurement range, the User should
follow the Measurement settings->Autorange menu command. The manufacturer
recommends turning on the automatic change of the measurement range. The manual
control is used for checking the linearity during the calibration or in the specific
conditions of the measurement when the measured value changes in time in such a way
that the instrument is incapable of determining the proper measurement range.

3.2.1.4. Additional actions

If the instruction manual of the attached probe requires the conduction of any
additional actions which are not included in Sec. 3.2.1, these activities should be
conducted.

3.2.2. Measurement triggering

To trigger the measurement, use Start/Stop measurement (see Sec. 2.4.
key which some measurement probes are equipped with. The key can also have

other functions, which depends on the currently running application.
The measurement time depends on the set operation mode.

1) or the

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● Single measurement mode – the measurement lasts for the set averaging time and

it stops automatically when the set time elapses.

● Continuous measurement mode – the measurement lasts until the key for starting

the measurement is pressed once again.
In the case of controlling the measurement triggering with the use of the probe key, the
measurement lasts until the key is released, but not shorter than the set averaging time.
If during averaging time at least one partial result is measured when measurement
range was exceeded, the measured value is considered to be erroneous and the proper
icon is displayed in front of the result (see Sec. 2.4.2). The icon is turned off after the set
averaging time has elapsed since the last exceedance. The measurement is stopped
after the trigger key is pressed again. The result is not refreshed then.

3.2.3. Averaging of results

The measurement value displayed in the measurement window consists of many partial
measurements taken from the attached probe. The displayed result is the arithmetic
average of all read values within the set averaging time. The frequency of reading partial
results from the probe depends on its type and is chosen so as not to omit any of them.
The averaging time is set in the menu Measurement setup->Averaging from the 1 – 10
seconds range. The result is refreshed every second and is the moving average from N
last seconds where N stands for the set averaging time.

3.2.4. Temperature compensation

The change in the temperature of the probe influences the measurement result. Due to
the temperature change, the other parameters also change and they are as follows:

● detector dark current - shift of zero indication

● offset voltage of the measuring circuit - shift of zero indication,

● responsivity of a detector - change of measured quantity value,

● gain of the measuring circuit - change of measured quantity value.

Measuring probes are equipped with the temperature sensor and functions that
minimise the influence of the above-mentioned factors on the measured value. The
compensation of zero indication occurs after the zeroing of the detector (see Sec.

3.2.1.1) or measuring circuit (see Sec. 3.2.1.2). Moreover, all measurement probes are
equipped with the function of automatic compensation of temperature influence on the
measurement result. That solution significantly expands the operating temperature
range minimising the measurement uncertainty.

3.2.5. Luminance mode

Illuminance/irradiance probes with the suitable adapter attached to them become
luminance/radiance meters – depending on the probe type. Each type of the measuring
probe has assigned permissions to adapters, with which they can work. The choice of
adapter is possible with the use of the Measurement setup->Luminance menu
command.

,

3.3. Calibration and adjustment of measuring probe

Calibration and adjustment procedure is the comparison of the measured values with
those of a calibration standard of known accuracy. On the basis of this comparison, the
calibration factor is calculated and saved to the measuring probe. Calibration should be
conducted by a competent laboratory equipped with the suitable instruments and the
proper photometric/radiometric standards. The calibration procedure is started with
Calibration menu command (see Sec. 2.2.5). In the calibration mode, the temperature

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compensation of the result is turned off; the temperature, in which the adjustment is
made, is measured with the probe and is the reference for the temperature
compensation algorithm.

The calibration procedure starts with the display of the results screen and the
measurement is started (see Fig. 3.1). After pressing the ENTER key, there displays a
screen on which the correct value of the measured quantity is entered (see Fig. 3.2). The
approval of the correct value leads to displaying the summary of the calibration. In the
new window there are displayed two calibration factors: the current one that is read
from the probe and the one that has just been calculated (see Fig. 3.3). The acceptance
of the new calibration factor results in saving it to the probe. At the end of the
procedure there is a message that informs about the success or failure of the calibration
and adjustment procedure.
The reasons for failure of calibration and adjustment procedure can be the following
ones:

● the exceeded range of calibration factor (the permis

● an error in saving the calibration factor to the mea

sible range is 0.01 – 9.99),

suring probe (e.g. due to

disconnecting the probe before the saving process is completed).

Before the final approval of the new calibration factor with the use of the ESC key it is
possible to go back to the previous step of the procedure.

Fig. 3.1. Calibration and adjustment procedure –

results screen view.

Fig. 3.3. Calibration and adjustment procedure - summary

Fig. 3.2. Calibration and adjustment procedure –

entering correct value.

3.4. Relative measurement

The relative measurement mode makes it possible to perform measurements whose
results are presented as the percentage value of the reference value.

This mode is turned on with the use of the Measurement setup->Relative menu
command. After choosing this option from the menu, there is a window used for
entering the reference value. The default value is the recently-measured value. There is
the main result expressed as a percentage displayed on the results screen. Besides, the

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reference value is displayed in the bottom left corner of the screen. The value measured
in the absolute units is shown in the top left corner of the screen (see Sec. 2.4).

3.5. Integration

Time integration of measurement results can be used to assess the hazards of optical
radiation with the use of the suitable measurement probes.

In photometry, the time integral of illuminance or luminance has no practical use.
However, the integration function can become useful in the measurement of the highly
variable values. Using the integration mode, the measurement should be conducted
until the average value of the measured quantity is steady. This value is the proper
measurement result and is the arithmetic average measured in integrating time. When
using the integration function, it is recommended to set the averaging time that
amounts to 1 second. In order to turn on the integration mode, use the
Measurement setup->Integration menu command. To turn it off, choose the single
(Measurement setup->Single) or continuous (Measurement setup->Continuous)
measurement mode. After the measurement is stopped, the integral and the statistics
related to it can be both deleted with the use of the
Measurement setup->Delete integral menu command.
On the result screen, the main result is the time integral of the measured quantity
expressed in units that are the products of the base unit and 1 second. In the top left
corner of the screen there is the currently-measured value and in the top right corner
there is the integration time. Below the main result there is the measurement statistics
that contains the following items:

● n

● min the minimum value of result saved in statistics,

● max the maximum value of result saved in statistics,

● avr the average value of result saved in statistics,

● mn/a the quotient of the minimum and average value,

● mn/x the quotient of the minimum and maximum value.

the number of measurements saved in statistics,

3.6. Statistics

This function allows you to conduct simple statistical operations on the measurement
results. The results may be, among others illuminance uniformity or contrast ratio. It is
possible to turn on the statistics in both single and continuous measurement mode
(while the integration is turned off) with the Statistics sub-menu. The
Statistics->Add measurement command adds the last measurement to the statistics. If
the statistics is turned off, then it is turned on. The Statistics->Auto add menu
command turns on or off automatic adding of every measurement to the statistics. After
turning on the auto add option, the statistics is turned on if it has been turned off
earlier. The Statistics->Clear all menu command deletes all the measurement results
from the statistics and it turns off this function.
On the result screen, below the main result there is the statistics that contains the
following items:

● n

● min the minimum value of result saved in statistics,

● max the maximum value of result saved in statistics,

● avr the average value of result saved in statistics,

● mn/a t

● mn/x the quotient of the minimum and maximum value.

the number of measurements saved in statistics,

he quotient of the minimum and average value,

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3.7. Measurements memory

T

his function allows you to save single measurements and create automatically their
history log. It saves the collected measurements to the text file which can be directly
open with the use of the spreadsheet software. The file contains the name of the
instrument type, its serial number, date and time of starting and ending measurement. A
new file is created at the moment of the first-time saving the measurement to memory
after the change of the instrument operation mode. It can also be created with the use
of the Memory->New file menu command.
It is possible to save it automatically to the memory with the Memory->Autosave menu

command or manually with the key on the results screen. In the case of the
automatic saving of data, the results are saved to the file within the set time interval
with the Memory->Interval menu instruction.

3.7.1. File name and format

The file name and its format depend on the instrument operation mode, in which it has
been saved. In each case a file name consists of a prefix, type of a used instrument and
starting date and time of measurements.

3.7.1.1. Absolute measurement

The file name starts with the Meas prefix, e.g. “Meas PCE-LMD 100 2018-01-01
12'00'26.txt”. The columns in the results sheet are as follows:

● no. successive measurement number,

● over exceedance of measurement range,

● result measured value,

● range measurement range of result,

● comment individual commentary on result (empty field).

3.7.1.2. Relative measurement

The file name starts with the Rel prefix, e.g. “Rel PCE-LMD 100 2018-05-22
12'10'48.txt”. The columns in the results sheet are as follows:

● no. successive measurement number,

● reference reference value for relative value calculation,

● over exceedance of measurement range,

● result measured absolute value,

● result % relative measured value,

● comment individual commentary on result (empty field).

3.7.1.3. Integration

The file name starts with the Int prefix, e.g. “Int PCE-LMD 100 2018-05-14 09'15'53.txt”.
The columns in the results sheet are as follows:

● time time,

● over exceedance of measurement range,

● result measured value of the integrated quantity,

● integral value of the integral for the time from the first column,

● quantity number of measurements in statistics of integration,

● min minimum value of results in statistics of integration,

● max maximum value of results in statistics of integration,

● average average value of results in statistics of integration,

● min/max quotient of minimum and maximum value,

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● min/average quotient of minimum and average value,

● comment individual commentary on result (empty field).

3.7.1.4. Statistics

The file name starts with the prefix Stat, e.g. ”Stat PCE-LMD 100 2018-01-01
14'01'46.txt”. The columns in the results sheet are as follows:

● no. successive measurement number,

● quantity number of measurements in statistics

● over exceedance of measurement range,

● last result value of last measurement in statistics,

● min minimum value of results in statistics,

● max maximum value of results in statistics,

● average average value of results in statistics,

● min/max quotient of minimum and maximum value,

● min/average quotient of minimum and average value,

● comment individual commentary on result (empty field).

3.8. Connection of instrument to PC

The question about the connection to a PC is displayed after the connection of the USB
cable to the instrument with the installed memory card. After choosing the Yes option,

the connection with the PC is established. The memory card is visible as an exchangeable
disc. The conduction of measurements is impossible. Choosing the Cancel option makes

the connection not established and the attached USB port is used only for charging the
battery. The instrument operates normally. At the end of the connection with the
computer, it is recommended to use the "Safely Remove Hardware" option available in
Windows.

4. APPLICATIONS

4.1. Medical monitors

This application is intended for measuring heads that are luminance meters. It allows
you to conduct tests of medical imaging monitors in accordance with the guidelines of
the American Association of Physicists in Medicine (AAPM).

It allows you to conduct the following tests:

● grayscale mapping curve according to DICOM GSDF 1,

● compliance of the maximum luminance between monitors of one station,

● luminance uniformity.

Only some measurement probes have access to this application. The detailed
information on the permissions to applications is included in the instruction manual of
the attached instrument. The tests can be conducted for a maximum of 8 monitors in
one diagnostic station. The results of all the tests can be labelled with one comment and
saved to the text file which can be open directly with a spreadsheet. The collected
results can also be open and pasted to the copy of the MonitorCheck.xls. spreadsheet
template.

1

DI

COM GSDF: Grayscale Standard Function according to PS 3.14-2011 Digital Imaging and

Communications in Medicine (DICOM) Part 14: Grayscale Standard Display Function.

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4.1.1. Operation of application

I

n order to run the application, use the Applications->Medical monitors menu
command. It is then necessary to choose a number of monitors in the diagnostic station.
After the confirmation of the number of monitors, there is some information displayed
on the screen which contains: the number of the tested monitor, the type of currently
conducted test and name of the test pattern to display (see Fig. 4.1). After pressing the
Start key, there comes up the results screen, on which the measurement should be
conducted (see Fig. 4.2).

g. 4.1. Medical monitors – information screen.

Fi

g. 4.2. Medical monitors – results screen.

Fi

After conducting the measurement, you can move further with the Next key or move
back to the previous step with the use of the Back key

ATTENTION! The choice of Back option results in the deletion of the current step.

fter all the measurements intended for the certain monitor are completed, the next

A
monitor is chosen and another cycle of measurements starts from the beginning. After
testing all the monitors it is possible to add a commentary that consists of a maximum of
16 characters. After the confirmation of the commentary the results are automatically
saved to the file whose name is automatically generated (see Sec. 4.1.3). The
mesurement data file is also saved after the approval of each partial result.

The application can be interrupted at any moment by holding down the ESC key for 3
seconds. This action results in the display of the window with the request for the
confirmation of the interruption. The application is interrupted when it is confirmed.

4.1.2. Conduction of tests

In order to conduct the tests, it is necessary to have test patterns files and the possibility
of displaying them on the controlled monitors. Each diagnostic station should be
equipped with such test patterns. These test patterns files are published by the
European Reference Organization for Quality Assured Breast Screening and Diagnostic
Services (EUREF) 2.
The procedure to be followed:

● Prepare the instrument for operation in accordance wi

th Sec. 3.1 and Sec. 3.2.

● Put the stabilising cap on the measurement probe if it is included in the set of
accessories.

● Set the proper result averaging time (see Sec. 2.2.3). The more unstable in time the
luminance value of the tested monitor is, the longer averaging time is.

● Run the application.

● Enter the number of tested monitors.

2

So

urce: http://www.euref.org/downloads/software-physico-technical-protocol/monitor-qc-test-patterns.

18

● Conduct a series of measurements.

● Enter the commentary. The data is saved to the text file.

4.1.3. Data file

The file name starts with the MonitorCheck prefix, starting data and time of
measurements, e.g. ”MonitorCheck 2018-01-01 14'01'46.txt”. All data is saved in the text
format and is tab-separated.

5. USAGE RECOMMENDATIONS

5.1. Internal battery

The instrument is operated normally with the use of the internal battery. It is, however,
necessary to connect the charger to the instrument in order to charge the battery. The
charging status is indicated with the LED placed under the micro USB connection (see
Fig. 1.1). The blinking of the LED diode indicates the battery charging process. After the
charging process is completed, the diode goes out. The process of charging is also
signalled on the results screen (see fig. 2.3).
If possible, the internal battery should be discharged completely (20% or less) before
being recharged. It is recommended to avoid the frequent recharging of partially
discharged battery because it reduces the battery life. The continuous operation with a
connected charger is possible.

ATTENTION! The battery is charged, regardless of the fact whether the instrument is turned
on or off!

19

5.2. Repairs and maintenance

The control unit does not require any special maintenance jobs.
All repairs of the instrument are performed by the Manufacturer.

6. CE MARKING AND WEEE DIRECTIVE

The product described in this instruction conforms to the following EU Council
Directives:

2014/30/EC Electromagnetic compatibility

conformance of the above-mentioned requirements is confirmed

The
by CE mark.

s product cannot be thrown away with household waste. Deposit

Thi
the product in an authorized electrical and electronic waste collection
area for recycling. Contact the local authorities or the nearest waste
disposal company to get more detailed information.

LUX METER

PCE-LMD 100

(PROBE)

INSTRUCT

ION MANUAL

TABLE OF CONTENTS

1. CHARACTERISTICS......................................................................................................................1

1.1. Equipment..............................................................................................................................1

1.2. CONFIGURATION .................................................................................................................1

1.2.1. Components of luminance meter .............................................................................2

1.3. Technical data ....................................................................................................................... 3

1.3.1. Spectral characteristics................................................................................................3

1.3.2. Directional characteristics ..........................................................................................4

1.4. Temperature compensation..............................................................................................4

1.4.1. Compensation of zero indication..............................................................................5

1.4.2. Temperature compensation of the result...............................................................5

2. THE PCE-LMD 100 METER OPERATION............................................................................... 5

2.1. Preparations .......................................................................................................................... 5

2.2. Measurement........................................................................................................................5

3. BASIC FUNCTIONS OF CONTROL UNIT ................................................................................. 6

4. EXTENDED FUNCTIONS OF CONTROL UNIT........................................................................6

4.2. Application: Medical monitors ..........................................................................................7

4.3. Application: Measurements memory ..............................................................................7

4.4. Application: Advanced ........................................................................................................7

4.4.1. Relative measurement................................................................................................. 7

4.4.2. Integration......................................................................................................................7

4.4.3. Statistics ..........................................................................................................................7

5. CALIBRATION AND ADJUSTMENT..........................................................................................7

6. MAINTENANCE RECOMMENDATIONS ................................................................................ 8

7. CE MARKING AND WEE DIRECTIVE ........................................................................................9

1. CHARACTERISTICS

The PCE-LMD 100 contact luminance meter is designed for the luminance
measurement of the self-luminescent surfaces such as monitor matrices, TV sets,
negatoscopes, reading panels, etc. The meter ensures the accurate measurement,
regardless of the spatial distribution of the measured luminance and the backlight
system of the surface being tested. It is indispensable for the co ntrol of the medical
imaging monito rs and negatoscopes. Its unique optical and measurement systems in
combination with the advanced algorithms of the measured signal processing guarantee
high accuracy and repeatability of measurements.
Owing to its technical parameters, the PCE-LMD 100 meter is classified as a class A
meter according to DIN 5032-7 and TC-2.2 CIE.
The meter consists of the measurement probe cooperating directly with the
control unit. The measurement probe is equipped with the multifunctional key that is
used to trigger a measurement, save results and operate the chosen measurement
procedure e.g. to test the reproduction of the grayscale of monitors according to
DICOM GSDF
application of the control unit.

1.1. Equipment

1 x PCE-LMD 100 environmental meter
1 x measuring probe
1 x micro USB charging cable
1 x 8 GB micro SD memory card incl. adapter
1 x attachment cap for the probe
1 x USB power supply
1 x operating instructions
1 x transport case

1)

function. The function of the key can be dependent on the running

1.2. CONFIGURATION

The control unit can be used to control the contact luminance meter and read the
measured values. The probe is connected directly to the control panel.

1)

DICOM GS
Communications in Medicine (DICOM) Part 14: Grayscale Standard Display Function.

DF: Grayscale Standard Function according to PS 3.14-2011 Digital Imaging and

- 1 -

The PCE-LMD 100 meter is powered with the use of the
control unit.

Fig. 1. Configuration of the PCE-LMD 100 measurement probe with the control panel.

1.2.1. Components of luminance meter

• measurement probe

• measurement module

Each of the above-mentioned components of the measurement system is
identifiable according to the requirements of ISO/IEC 17025 standard.

- 2 -

1.3. Technical data

Spectral sensitivity:

V(λ) CIE
Measurement field angle: 1
Measurement field: Ø
Spectral matching:
Directional response index:
Effect of the surrounding field:
Linearity:
Temperature coefficient:
Measurement ranges 3):

500 cd/m

f1'

f

2

f

2

f3

KT ≤

50 000 cd/m2
Measurement resolution: 0.

1 cd/m2 (range 50 000 cd/m2)
Total error 4):

+10°C – +40°C 2.5%

0°C – +50°C 3.0%

-1
Power supply: wi
Environmental conditions

temperature:

-

- relative humidity:

-10°C ÷ +50°C
≤90% (without condensation)

Dimensions

- measurement probe:
interface:

-

Ø25 x 160mm
Ø15 x 42mm

Measurement probe weight: 15

º

10mm

)

2

≤ 3%

2

)

≤ 3%

g

)

2

≤ 1,5%

u

)

2

≤

0,5%
0,02%/K

2

01 cd/m2 (range 500 cd/m2)

th control unit (5V, 25mA)

0g

3.1. Spectral characteristics

1.

Very good spectral matching of the detector to the spectral sensitivity V(λ) is realised
with the use of the set of glass absorption filters. Such a solution guarantees high long­term and temperature stability, especially in comparison with the cheaper realisations in
which interference filters are used. The quality of this kind of matching ensures the
accurate measurement, regardless of the spectral distributions of the measured
luminous flux, which in the used systems of matrix backlights vary to a great extent from
the spectral efficiency of the calibration illuminant and are the main source of errors.

2)

SO/CIE 19476 Characterization of the performance of illuminance meters and luminance meters (this standard

I
replaces CIE publication 69/1987).
DIN 5032-7 Photometry; Classification of illuminance meters and luminance meters

3)

The specified measuring ranges are the minimum values guaranteed by the manufacturer. The actual
values depend on the sensitivity of the detector and the calibration factor and can be even twice as
high.

4)

The percentage deviation of the measured value for white light sources with any spectral distribution in
the given operating temperature range. It takes into account all the factors affecting the accuracy of
the measurement (spectral and directional mismatch, temperature influence and others). It does not
include the uncertainty of calibration.

- 3 -

Fig. 3. Typical spectral sensitivity of the probe.

1.3.2. Directional characteristics

The unique optical system of the measurement probe ensures an identical assessment
of every point of the tested surface. The special attention should be paid to the fact that
the countersink angle for the cone of rays reaching the detector from every point of the
tested object is identical with the measurement field angle, which is unachievable for
standard luminance meters and can become the source of serious measurement errors
for them. Such shape of the beam of rays is the main attribute for the
measurement probe and its enormous advantage over other meters available on the
market. Therefore, the influence of luminance irregularity of the monitor matrix for
various directions of observations is negligible.

Fig. 4. Directional response of the probe.

1.4. Temperature compensation

The change in the temperature of the probe influences the measurement result. Due to
the temperature change, the other parameters also change and they are as follows :

● detector dark current - shift of zero indication,

● offset voltage of the measuring circuit - shift of zero indication,

● responsivity of a detector - change of measured quantity value,

-

4 -

●

gain of the measuring circuit - change of measured quantity value.

Measuring probes are equipped with the temperature sensor and functions that
minimise the influence of the above-mentioned factors on the measured value.

1.4.1. Compensation of zero indication

Compensation of zero indication occurs after zeroing of the detector or the measuring
circuit. It is realised with the aid of the functions which the probe is equipped with.
For compensation of zero indication it is necessary to use the following commands of
the control device:

• Zeroing of detector. The zeroing procedure of the detector consists in the

measurement of the dark current of the measurement probe detector and its
corresponding temperature. It can be conducted only with the covered reception
field of the probe. The value of the dark current and the temperature of the zeroing
are saved to the memory of the measurement probe.

• Zeroing of measurement system. The zeroing procedure of the measurement system

consists in the direct measurement of the correction that results from the measuring
circuit offset voltage which is deducted from the result. It is automatically conducted
after the probe is connected to the control unit and whenever the detector is zeroed.
The value of the correction and the temperature of the zeroing are saved to the
memory of the probe.

1.4.2. Temperature compensation of the result

Alongside the use of the high-class elements in the design of the meter, the probe
is equipped with the automatic compensation system of the influence of the
environmental temperature on the measurement value. The temperature in which the
calibration is conducted is the reference to the correction factor being then calculated
for the current temperature. The influence of the ambient temperature on the
measurement value is virtually possible to be omitted for typical usage.

2. THE METER OPERATION

2.1. Preparations

• Connect the probe to the control unit.

• Start the measurement.

• Check the zero indication with the covered reception field of the probe and

alternatively, conduct zeroing of the detector.

• Remove the cap from the probe. The instrument is ready to operate.

2.2. Measurement

• The stabilising cap should be put on the probe when larger surfaces are tested.

• Set the result averaging time in the control unit. The more unstable in time the value

of the measured quantity is, the longer the time should be. In most applications the
sufficient averaging time amounts to 1s

• Choose the automatic or manual change of the measurement range. It is

recommended by the manufacturer to turn on the automatic change of the range.
The manual control is intended for the procedures of checking linearity during
calibration or in specific conditions of measurement when the value of the measured
quantity changes in time to such an extent that the control unit cannot determine
the proper measurement range.

• Place the measurement probe perpendicular to the measured surface.

- 5 -

• Trigger the measurement with the key on the probe or with the certain key on the

control unit.
In the case of the tested medical imaging monitors it is necessary to use the application
of the control unit intended for this kind of measurement.

3. BASIC FUNCTIONS OF CONTROL UNIT

The basic functions of the control unit are the following ones:

• Zeroing of the detector.

• Zeroing of the measurement system.

• Manual or automatic choice of the measurement range.

• Choice of the single or continuous measurement mode.

• Choice of the averaging time in range from at least 1-10s

5)

. The measurement result

is the moving average that is refreshed every 1s.

• Triggering and stopping the measurement.

• Calibration and adjustment of the meter.

4. EXTENDED FUNCTIONS OF CONTROL UNIT

The control devices are equipped with applications or functions that extend the range of
the probe usage. All the applications have the possibility of archiving of the
measurements results to a microSD card . The data is saved in text files, where tabs
are separation signs. Such a file format enables the User to open it directly with the
help of the spreadsheet. The access rights to the certain application depend on the type
of the attached measurement probe.

5)

T

he range of values of the result averaging time depends on the control unit.

- 6 -

4.2. Application: Medical monitors

The correct assessment of medical imaging monitors in a diagnostic station requires the
use of the luminance meter whose technical solutions and metrological parameters
comprise all aspects related to various designs of monitor matrices. The meter of this
kind is the PCE-LMD 100 which is, above all, intended for this type of tests as it
guarantees very high measurement accuracy. The contact luminance meter meets
the guidelines of the American Association of Physicists in Medicine (AAPM) as well as
the users’ expectations.
The manufacturer still has assigned for the probe the rights to the application of
medical monitors because its metrological parameters conform to the requirements of
this type of tests. Another condition for luminance measurement is the use of the
suitable adapter.

4.3. Application: Measurements memory

The control units are used to archive the measurements conducted with the use of the
probe. It is possible to save one single measurement or chosen measurements as well as
to create the measurement history log within any time interval.

4.4. Application: Advanced

4.4.1. Relative measurement

The control units enable to conduct and archive the measurements whose results
are expressed as a percentage of any reference. It is possible to save one
single measurement or chosen measurements as well as to create the measurement
history log within any time interval.

4.4.2. Integration

The control units are used to conduct and archive the measurements which are the time
integral of the partial results. The last result or the whole measurement history log can
be saved to the memory.

4.4.3. Statistics

The control units enable to conduct and archive the measurements as well as to
make simple statistical operations on the results. The last result or the whole
measurement history log can be saved to the memory.

5. CALIBRATION AND ADJUSTMENT

Calibration is the comparison of the measured values with those of a calibration
standard of known accuracy. On the basis of this comparison, the calibration factor
is calculated and saved to the measuring probe. The control units allow the User
to conduct the adjustment procedure of the measurement probe. The procedure
should be conducted by a competent laboratory equipped with the suitable instruments

- 7 -

and the proper photometric standards that are indispensable for setting the reference
illuminance in the reception field of the probe. It is necessary to take into account
the fact that adjustment is related to all the components of the meter specified in Sec.

1.2.1.

6. MAINTENANCE RECOMMENDATIONS

• The measurement probe must be connected only to the devices described in the

instruction manual.

• The device

mechanical damage.

• It is necessary to protect the optical element of the reception field from dirt.

• The lens can be dusted with a clean, soft brush or with the airstream of the

compressed dry air after unscrewing the element of the probe with an entry hole.
It is recommended to rely on the latter method. Spray preparations that act as
compressed air should be applied gently and very carefully. The container with such
spray should be held in a vertical position.

• The probe cap should be removed only during the measurement.

• The probe should be removed and put on while turning it right clockwise, which

prevents it from being untwisted by accident.

• The instrument should be kept and transported only in the carrying case provided by

the manufacturer.

• All repairs of the instrument are performed by the manufacturer.

should not be exposed to falls, shocks or any other factors which can cause

- 8 -

7

. CE MARKING AND WEE DIRECTIVE

The product described in the instruction conforms to the following EU Council
Directives:

2014/30/EC Electromagnetic compatibility

The conformance of the above-mentioned requirements is confirmed by CE mark.

This product cannot be thrown away with household waste. Deposit the product in

a

uthorized electrical and electronic waste collection area for recycling. Contact

an
the local authorities or the nearest waste disposal company to get more detailed
information.

- 9 -