Sonel LXP-2 Digital Light Meter User Manual

: June 5, 2024
: Sonel

Sonel LXP-2 Digital Light Meter User Manual

Features

Digital data-logging light meters are precision instruments used to measure illuminance (lux and foot-candles) in field conditions.

They meet the requirements of CIE spectral sensitivity curves for spectral response. Their photo element is cosine-corrected.

The meters are compact and durable units thanks to their simple-to-use design.
The photosensitive element used in these meters consists of a very stable and durable silicon photodiode and spectral sensitivity filter.

The most important features of the devices include:

maximum resolution of light metering: 0.1 lx (0.01 fc) – LXP-2, 0.01 lx (0.001 fc) – LXP-10B, 0.001 lx (0.0001 fc) – LXP-10A,
high accuracy and fast response time,
Data-hold function for holding the measured values displayed on the screen,
automatic reset,
no need to use correction factors for different light sources, thanks to a very good adjustment of spectral sensitivity ensuring correct measurements of light intensity regardless of the nature of radiation,
short response times to changing light intensity,
“Peak-hold” function that enables the user to measure the peak signal of light pulse longer than
0.1 s (0.4 s for LXP-2 with probe LP-1) and shorter than 1 s,
automatic power off after 5, 10 or 15 minutes, or auto-off function
measurements of maximum and minimum values,
relative readings,
large and readable display with backlit function;
USB socket for connecting the meter to a PC,
data transmission via wireless (radio) link with an optional adapter OR-1 (only LXP-10B, LXP-10A),
Four measuring ranges – LXP-2, five measuring ranges – LXP-10B, six measuring ranges – LXP-10A,
memory space for 99 results (LXP-2) or 999 results (LXP-10B, LXP-10A), that may be read on the meter or on a PC,
data logger with a logging capacity of 16000 values.

Functional Description

Description of the device

Power Button: Turns the light meter ON/OFF.
Liquid crystal display 3 3/4″: digital display with a maximum reading of 3999, showing the symbols of the measured values, symbols of functions, etc.
RANGE button: Manual change of the range or switching it to automatic.
LOGG button: turning data logger or backlight ON/OFF, erasing data logger memory.
ENTER/MEM button: Entering values into the measurement memory, viewing and deleting the measurement memory.
SET button: Entering the meter settings.
HOLD button: Holding the displayed data or “up” cursor.
PEAK: Holding the peak values or “right” cursor.
MAX/MIN button: Reading the maximum or minimum value; or “left” cursor.
REL button: Relative measurement or “down” cursor.
Measuring head with a sensor.

Display

The main read-out field.
Bar graph – analogue scale for showing rapid changes in light intensity.
Additional reading field
Symbols of sampling period and units.
Symbols for setting date and time.
Units.
Symbol of data logging.
Symbol of memory.
Additional reading field
Units.
Symbol of relative measurement.
Discharged battery symbol.
Symbol of MIN / MAX values (also for PEAK HOLD function).
Symbol of HOLD function.

Settings

Use SET button to enter the meter settings. The buttons and are used to set the parameter value, while and buttons are used to move to the next parameter. Settings are introduced in the following order:
unit (lx or fc) → sampling period (every 1 s…60 s) → day → month → year → hour → minute → second → sounds (On/Off) → AutoOFF (300 s, 600 s, 900 s, none (—)) → unit …
Exit settings by pressing SET – selected/changed settings will be saved.

Taking measurements

Press the power button in order to switch the meter ON.
The device is in the automatic range selection mode. To enter the manual range selection mode, press RANGE button for 2 sec. Ranges are switched by short pressing of RANGE button. The range is displayed at the top of the display. Pressing the button again for 2 seconds will return the device to the automatic range selection mode.
Remove the cover from the photodetector and point it perpendicularly to the light source.
Read the nominal value of the lighting from the display.
If the instrument displays only “OL” symbol, it means that the input signal is too strong and you need to set a higher measuring range.
After completing the measurement cover the photodetector with its cover and turn the meter OFF.

Special Features

DATA HOLD mode for holding displayed data

Press HOLD button to select the Data Hold mode. When HOLD mode is selected, the meter stops the currently displayed result and shows it as numbers, whereas the bar graph continues to show actual indications.
Press again HOLD again to exit Data Hold mode, the meter returns to normal operation.

PEAK HOLD function for read-out of peak values

PEAK HOLD function enables the user to measure the peak signal of light pulse longer than 0.1 s (0.4 s for LXP-2 with probe LP-1) and shorter than 1 s. The bar graph shows current result continuously.

Press PEAK to enter Pemex data logging mode and place the device in the light measuring area.
Press PEAK button again to enter PMing data logging mode.
Press PEAK button again to exit Peak Hold mode and return to normal operation.

Maximum and minimum value mode

Press MAX/MIN button to read the maximum value (MAX).
Press MAX/MIN button again to read the minimum value (MIN).
Press MAX/MIN button again exit this mode and return to normal operation mode.
The bar graph shows current result continuously.

Relative mode measurement

Press REL button to start the relative mode measurement. The displayed result is the difference between the currently measured value and the reference value saved in the moment of pressing REL button. If the new reading is identical to the reference value, then the display will show zero. The bar graph shows current result continuously.
Press REL again to exit the relative measurement.

USB Mode

Connect the device to your computer via the USB port.
Start the program Sonel Reader on your computer.
The meter operates in data reading mode.
To read the data stored in memory, use the appropriate commands in the software. The software enables the user to select the type of the read memory: measurement memory or data logger memory.

Wireless (radio) transmission mode (only LXP-10)

Connect the OR-1 module to the PC USB socket.
Start Sonel Reader software.
In order to activate radio transmission function, press SET button and hold it pressed for 2 seconds. Instead of showing the measurement range, the display will show message:
Displaying the measurement range is the same as in USB mode.
To exit the function, again hold SET button pressed for 2 seconds.

Note:
Standard PIN code for wireless (radio) transmission is “123”.

Display backlight

Press the backlight button briefly to switch it ON.
Press the backlight button briefly again to switch it OFF.

Memory function

To save the current data in memory, press ENTER/MEM button and the display will show MEM for
3 seconds along with the cell number in which the measurement will be saved. Each new measurement is saved automatically to the next available cell. When the memory is full, then after pressing ENTER/MEM, instead of a cell number, the display will show ‘—‘ and the measurement will not be saved.
To read measurement results from the memory – press and hold ENTER/MEM button pressed for 2 seconds. Use and buttons to scroll individual memory cells. The device will display: measured value, unit, date and time of measurement (use and buttons) and information on memory – main (general) memory or memory of individual functions e.g. Pmax, Pmin, MAX, MIN, REL. The same data may also be accessed from your PC.
I order to return to the normal operation mode – press and hold ENTER/MEM button for 2 seconds.
To clear the memory, turn the meter ON while holding down ENTER/MEM button. The process of erasing the memory lasts about 10 seconds. The main display will show and the cell number display field will show numbers of cells decreasing to zero, indicting remaining cells to be erased. After erasing the memory, the meter returns to the measurement mode.

Data Logging function

Set the time and the sampling rate according to par. 2, the default sampling rate is 1 sec.
To start the data logging function, press and hold LOGG button for 2 seconds, the display will show LOGG and free memory space will be displayed as a percentage value (from 100 to 0). The memory stores data on measured value, its unit, date and time.
LOGG will blink at intervals equal to the set sampling period, indicating when the measurement is taken.
When the memory is full, then the percentage value shown is 0 and a double beep is generated to indicate ending the data logging process. If data logging mode is activated when the meter memory is full, the meter after 2 seconds will exit this mode and LOGG symbol will disappear – after that a double beep is generated.
To stop the data logging function, press and hold LOGG button for 2 seconds, the meter will return to the normal operation mode, data logging may be started from the beginning.
As data is logged in a separate memory, different than a single measurement, the user may save single measurement results. This may be done by pressing MEM/ENTER button. In such case, the display apart from LOGG symbol will additionally show MEM, and instead of the percentage value of free memory space, the device will display the number of memory cell where the measurement is saved.
To clear the memory of the meter, turn the meter ON while holding down LOGG button. The main display will show and the percentage value field will show the amount of free space that will change from 0 to 100% when erasing progresses. After erasing the memory, the meter returns to the measurement mode.
Logged data may be read only with the PC software provided with the meter.

Characteristics of spectral sensitivity

Installed photodiodes with filters makes the spectral sensitivity characteristics well matched to the requirements of C.I.E. (INTERNATIONAL COMMISSION ON ILLUMINATION). Sensitivity parameters V (λ) are presented on the following charts.

Characteristics of
spectral sensitivity
Fig. 1 Characteristics of spectral sensitivity

Recommended lighting

LOCATION

|

lx

|

fc

---|---|---
OFFICE|

Conference room, reception

| 200~750| 18~70
Office work| 700~1,500| 65~140
Typing, designing| 1,000~2,000| 93~186
FACTORY| Visual works on the production line| 300~750| 28~70
Inspection works| 750~1,500| 70~140
Electronic components, assembly line| 1,500~3,000| 140~279
Packaging, corridors| 150~300| 14~28
HOTEL| Public rooms, cloakroom| 100~200| 9~18
Reception| 200~500| 18~47
Cash register| 750~1,000| 70~93
SHOP| Interiors, stairs, corridors| 150~200| 14~18
Display window, packing table| 750~1,500| 70~140
The front side of a display window| 1,500~3,000| 140~279
HOSPITAL| Patient room, store| 100~200| 9~18
Room for medical examination| 300~750| 28~70
Operating theatre, emergency cases| 750~1,500| 70~140
SCHOOL| Assembly hall, interiors, gym| 100~300| 9~28
Classrooms| 200~750| 18~70
Laboratory, library, labs| 500~1,500| 47~140

1 fc=10,76 lx

Connection

Turn on the meter,
activate USB mod (see section 4.5) or radio transmission mode (see section 4.6),
Start Sonel Reader software to operate the meter.

Note: switch OFF the light meter before connecting USB cable to the meter socket.

Replacing the battery

Note:
While performing the measurements with the battery symbol displayed, the user must be aware of additional measurement uncertainties or unstable operation of the device.

If the battery power is not sufficient to perform the measurements, the display will show the discharged battery symbol, indicating the need to replace the battery with a new one.
After the meter is turned OFF, open the battery compartment cover.
Remove the old battery from the device and replace it with a standard 9V battery, then re-attach the cover.

Cleaning and maintenance

White plastic disc on top of the detector should be cleaned with a damp cloth (if necessary).
Do not store the device in conditions of excessive heat or humidity.

Calibration interval for the photodetector will vary depending on the operating conditions, but in general, its sensitivity is reduced in direct proportion to the product of light intensity and operating time. In order to maintain the basic accuracy of the meter, we recommend periodic calibration.

Storage

During the storage of the device, the following recommendations must be observed:

disconnect the probe from the meter
make sure that the meter and accessories are dry,
when the device is to be stored for longer time, remove the batteries

Dismantling and disposal

Worn-out electric and electronic equipment should be gathered selectively, i.e. it must not be placed with waste of another kind.

Worn-out electronic equipment should be sent to a collection point in accordance with the law of waste electrical and electronic equipment.

Before the equipment is sent to a collection point, do not dismantle any elements. Observe local regulations concerning disposal of packages, waste batteries and accumulators.

Technical specifications’

displaying the result in lx or fc
1 fc=10.76 lx; 1 klx=1000 lx; 1 kfc=1000 fc

Meter| Probe| Class| Display range [lx]| Resolution [lx]| Accuracy| Spectral uncertainty f 1 ’| Cosine mat ching error f 2
---|---|---|---|---|---|---|---
LXP-2| LP-1| B| 0…399.9| 0.1| ±(5%+5 digits)| ±6%| ±3%
400…3999| 1
4.00 k…19.99 k| 0.01 k
LXP-10B| LP-10B| B| 0…39.99| 0.01| ±(5%+5 digits)| ±6%| ±3%
40.0…399.9| 0.1
400…3999| 1
4.00 k…39.99 k| 0.01 k
40.0 k…399.9 k| 0.1 k
LXP-10A| LP-10A| A| 0…3.999| 0.001| ±(2%+5 digits)| ±2%| ±1.6%
4.00…39.99| 0.01
40.0…399.9| 0.1
400…3999| 1
4.00 k…39.99 k| 0.01 k
40.0 k…399.9 k| 0.1 k
LXP-2| LP-1| B| 0…39.99| 0.01| ±(5%+5 digits)| ±6%| ±3%
40.0…399.9| 0.1
400…1999| 1
LXP-10B| LP-10B| B| 0…3.999| 0.001| ±(5%+5 digits)| ±6%| ±3%
4.00…39.99| 0.01
40.0…399.9| 0.1
400…3999| 1
4 k…39.99 k| 0.01 k
LXP-10A| LP-10A| A| 0…3.999| 0.001| ±(2%+5 digits)| ±2%| ±1.6%
4.00…39.99| 0.01
40.0…399.9| 0.1
400…3999| 1
4.00 k…39.99 k *| 0.01 k

displaying fc result with reduced resolution due to the display limitations.

Other technical data

display: 3-3/4″ digital LCD with 40-segment bar-graph
exceeding the range: “OL” symbol
Spectral sensitivity: CIE spectral sensitivity (CIE human eye sensitivity)
sampling rate: 1.3 Hz
photodetector: one silicon photodiode and spectral sensitivity filter
memory
- LXP-2: 99 results
- LXP10B and LXP-10A: 999 results
recorder memory: 16000 results
working temperature: 0°C…50°C
operational relative humidity: 0%…80%
storage temperature: -20°C…70°C
power source: 9 V battery or 8.4 V rechargeable battery
length of the measuring probe: approx. 150 cm
dimensions of the measuring probe: 115 × 60 × 20 mm
dimensions of the control panel: 170 × 80 40 mm
weight: 390 g
interface: USB and wireless link (only LXP-10B and LXP-10A)

Accessories

The current list of accessories can be found on the manufacturer’s website.

Standard accessories

The standard set of equipment supplied by the manufacturer includes:

control panel for LXP-2 or LXP-10,
9V battery,
measuring probe LP-1, LP-10B or LP-10A,
Note: LP-1 probe is not compatible with LXP-10A(B) panel
USB cable,
user manual,
guarantee card,
hard case,
calibration certificate.

Service

The provider of guarantee and post-guarantee services is:

SONEL S.A.
Wokulskiego 11 58-100 Świdnica Poland
tel. +48 74 858 38 60
fax +48 74 858 38 09
E-mail: export@sonel.pl
Web page: www.sonel.pl

Note:
Service repairs must be performed solely by SONEL S.A

Laboratory services

SONEL Testing and Calibration Laboratory has been accredited by the Polish Center for Accreditation (PCA) – certificate no. AP 173.

Laboratory offers calibration for the following instruments that are used for measuring electrical and non-electrical parameters.

METERS FOR MEASUREMENTS OF ELECTRICAL PARAMETERS
- voltage meters,
- current meters (including clamp meters),
- resistance meters,
- insulation resistance meters,
- earth resistance and resistivity meters,
- RCD meters,
- short-circuit loop impedance meters,
- power quality analyzers,
- portable appliance testers (PAT),
- power meters,
- multimeters,
- multifunction meters covering the functions of the above-mentioned instruments,
ELECTRICAL STANDARDS
- calibrators,
- resistance standards,
METERS FOR MEASUREMENTS OF NON-ELECTRICAL PARAMETERS
- pyrometers,
- thermal imagers,
- luxmeters.

The Calibration Certificate is a document that presents a relation between the calibration standard of known accuracy and meter indications with associated measurement uncertainties. The calibration standards are normally traceable to the national standard held by the National Metrological Institute.

According to ILAC-G24 „Guidelines for determination of calibration intervals of measuring instruments”, SONEL S.A. recommends periodical metrological inspection of the instruments it manufactures no less frequently than once every 12 months.

For new instruments provided with the Calibration Certificate or Validation Certificate at the factory, recalibration should be performed within 12 months from the date of purchase, however, no later than 24 months from the date of purchase.

ATTENTION !
The person performing the measurements should be absolutely sure about the efficiency of the
device being used. Measurements made with an inefficient meter can contribute to an incorrect
assessment of the effectiveness of health protection and even human life.

SONEL S.A. Wokulskiego 11 58-100 Swidnica Poland

PL
+48 74 858 38 00
(Biuro Obstugi Klienta)
e-mail: bok@sonel.pl

GB • ES • RU
+48 74 858 38 60
+48 74 858 38 00
fax: +48 74 858 38 09
e-mail: export@sonel.pl

www.sonel.pl