Interacoustics OtoRead User manual

Instructions for Use ─US
OtoRead™
D-0116685-A – 2017/02

Table of Contents
1INTRODUCTION ..............................................................................................................................1
2UNPACKING AND INSTALLATION................................................................................................5
Environmental factors............................................................................................... 8
Electrical and electrostatic safety ............................................................................. 9
Electromagnetic compatibility (EMC)........................................................................ 9
Explosion hazards .................................................................................................... 9
Measuring security.................................................................................................... 9
Miscellaneous........................................................................................................... 9
Use of equipment after transport and storage........................................................ 10
Battery charging...................................................................................................... 12
Installing the MPT-II printer..................................................................................... 12
Switching the printer on and off.............................................................................. 12
Light indicators........................................................................................................ 12
Using the printer ..................................................................................................... 13
The OtoReadTM test instrument.............................................................................. 13
Charging and powering the OtoReadTM.................................................................. 14
2.6.2.1 The battery.............................................................................................. 14
2.6.2.2 Battery lifetime and charging time........................................................... 15
2.6.2.3 Indication lights on OtoReadTM................................................................ 15
2.6.2.4 Connecting the Micro-Probe to the OtoReadTM....................................... 15
3OPERATING INSTRUCTIONS ......................................................................................................17
Battery charge status indicator............................................................................... 18
General................................................................................................................... 19
Attaching ear tips.................................................................................................... 19
Removing ear tips................................................................................................... 19
The probe tube ....................................................................................................... 20
Selecting the Test Protocol..................................................................................... 21
Select the test ear................................................................................................... 22
Probe check............................................................................................................ 22
Calibration after probe check.................................................................................. 22
Testing children with PE tubes ............................................................................... 23
Test phase.............................................................................................................. 23
Storing results......................................................................................................... 23

Viewing results........................................................................................................ 24
Viewing DPOAE results with normative data.......................................................... 24
Rounding results..................................................................................................... 25
General................................................................................................................... 26
Saving results......................................................................................................... 26
Deleting results....................................................................................................... 26
Printing to a thermal printer .................................................................................... 27
Connection to the PC module................................................................................. 28
Menu Structure....................................................................................................... 29
Accessing the menus.............................................................................................. 29
Date and time settings (menu M1) ......................................................................... 31
3.11.3.1 Setting initial date and time..................................................................... 31
3.11.3.2 Daylight saving time................................................................................ 31
3.11.3.3 Changing the date and time.................................................................... 31
Device settings (menu M2)..................................................................................... 32
3.11.4.1 Wireless device pairing ........................................................................... 32
3.11.4.2 Clearing test results................................................................................. 32
3.11.4.3 Power mode ............................................................................................ 33
3.11.4.4 Save mode / storing test results.............................................................. 33
3.11.4.5 Minimum value ........................................................................................ 34
3.11.4.6 Clock mode ............................................................................................. 34
3.11.4.7 Graph style.............................................................................................. 34
3.11.4.8 Language ................................................................................................ 35
3.11.4.9 Reset to default ....................................................................................... 35
Advanced options for DPOAE testing (DP menu)................................................. 35
3.11.5.1 General.................................................................................................... 35
3.11.5.2 Customizing a test protocol..................................................................... 36
3.11.5.3 Changing the levels................................................................................. 36
3.11.5.4 Setting the averaging time....................................................................... 36
3.11.5.5 Setting the PASS SNR level ................................................................... 37
3.11.5.6 Setting the number of frequencies for PASS .......................................... 37
3.11.5.7 Reset protocol ......................................................................................... 37
3.11.5.8 Save protocol .......................................................................................... 38
Advanced options for TEOAE testing (TE menu)................................................... 38
3.11.6.1 General.................................................................................................... 38
3.11.6.2 Customizing a test protocol..................................................................... 38
3.11.6.3 Setting the averaging time....................................................................... 39
3.11.6.4 Setting the PASS SNR level ................................................................... 39
3.11.6.5 Setting the number of frequencies for PASS .......................................... 39
3.11.6.6 Reset protocol ......................................................................................... 40
3.11.6.7 Save protocol .......................................................................................... 40
4CARE AND MAINTENANCE .........................................................................................................41
5TROUBLESHOOTING ...................................................................................................................45
6GENERAL TECHNICAL SPECIFICATIONS.................................................................................47

7APPENDICES.................................................................................................................................55

OtoRead™ Instructions for Use - US Page 1
1 Introduction
About this manual
This manual is valid for the OtoRead™ (valid from version 3.20). This product is manufactured by:
Interacoustics A/S
Audiometer Allé 1
5500 Middlefart
Denmark
Tel.: [phone]
Fax: [phone]
E-mail: [e-mail]
Web: www.interacoustics.com
1.2 Intended use
The OtoRead™ Otoacoustic Emission Test Instrument is designed to be a screening device for hearing loss
in infants, children, and adults by measuring otoacoustic emissions (OAE).
This instrument is suitable for use in all settings, including hospitals, schools, physicians’ offices, and
audiologists’ practices. The OtoRead™ is intended to be used by hearing healthcare professionals (i.e. ENT
doctors, audiologists) and/or technicians, neonatal nurses and school nurses who have been trained by a
hearing healthcare professional.
1.3 Definition of OAEs
What are DPOAEs?
Distortion Product Otoacoustic Emissions (DPOAEs) are acoustic signals that can be detected in the ear
canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a
pair of pure tones at frequencies f1 and f2. The resulting emission of interest is the distortion product tone at
the frequency 2f1 - f2.
What are TEOAEs?
Transient Evoked Otoacoustic Emissions (TEOAEs) are acoustic signals that can be detected in the ear
canal of a person with normal outer hair cell function, subsequent to stimulation of the auditory system with a
series of wideband clicks.
What do Otoacoustic Emissions results tell us?
Available evidence suggests that otoacoustic emissions (OAEs) are generated by the cochlea’s outer hair
cells, and that the presence of OAEs is an indication that the outer hair cells are normal. Although OAE test
data provide no indication of inner hair cell function, or of hearing ability, current research indicates that the
majority of hearing-impaired individuals will be identified by a simple OAE test. Patients who fail to generate
OAEs should be rescreened and/or referred for additional audiological testing.
How does the OtoReadTM device measure DPOAEs?
The OtoReadTM instrument generates a series of test tones, directs them into the ear canal, and then
measures the level of the DPOAE tone generated by the cochlea. By using different test frequencies, the
OtoReadTM device provides an estimate of outer hair cell function over a wide range of frequencies.

OtoRead™ Instructions for Use - US Page 2
How does the OtoReadTM device measure TEOAEs?
The OtoReadTM instrument generates a series of clicks, directs them into the ear canal, and then analyzes
the spectrum of the returning signal, separating the noise from the emission. By using band pass filters, the
OtoReadTM device provides an assessment of outer hair cell function over a wide range of frequencies.
What frequency range of hearing is assessed?
DPOAEs: Approximately 1 kHz to 12 kHz (depending on the frequency range selected). Since the health of
the hair cells in the region of the f2 test frequency is assessed, and a) the 2f1-f2 emission frequency is at
about six-tenths of the f2 frequency, b) emissions tend to be weak below 600 Hz or so, and c) the ambient
noise tends to be highest at low frequencies, the lowest f2 test frequency that can be routinely measured is
about 1 kHz.
TEOAEs: Roughly 500 Hz to 4 kHz. TEOAEs can be reliably recorded at lower frequencies than DPOAEs,
but cannot be measured reliably above 4 kHz.
1.4 Contraindications
Contraindications to testing include recent stapedectomy or middle ear surgery, a discharging ear, acute
external auditory canal trauma, discomfort (e.g, severe otitis externa) or occlusion of the external auditory
canal. Testing should not be performed on patients with such symptoms without a medical doctor’s approval.
For US only: Federal law restricts the sale, distribution, or use of this device to, by, or on the order of a
licensed medical practitioner.
1.5 Product description
The OtoReadTM is a hand-held device designed to provide an objective measure of outer hair cell function
through the measurement of cochlear emissions. It consists of the handheld unit, printer, single-use eartips
and other accessories.
Factory-defined protocols allow for simple screening measurements (Screener and Screener+ Version) and by
using customizable protocols it can also assist in diagnostic evaluations (Standard and Clinical Version).
The purpose of the OtoReadTM test system is to provide rapid measurement and documentation of Distortion
Product Otoacoustic Emissions (DPOAEs) or Transient Evoked Otoacoustic Emissions (TEOAEs) at several
frequencies. The digital signal processor in the instrument generates two pure tones (f1 and f2) for DPOAEs
or a series of wideband clicks for TEOAEs through a digital-to-analog converter. These tones or clicks are
presented to the ear via speaker tubes located in the probe. A microphone in the probe measures the sound
in the ear canal and transmits the signal to the analog-to-digital converter. The digital signal processor then
uses Fast-Fourier Transforms (FFTs) to filter the signal into narrow frequency bands, and detects any
emissions present. The level of these emissions can be compared with the level of the noise. The SPL and
frequencies of the test tones and the averaging time used to process the signals can be determined by the
tester through adjustable settings maintained in static memory within the OtoReadTM instrument.
The OtoReadTM instrument may be used as a screening tool or in conjunction with conventional tests as part
of a full audiological evaluation.

OtoRead™ Instructions for Use - US Page 3
The system consists of the following included and optional parts:
Included Components
Item Number
OtoReadTM device
8504335
Micro-Probe1
8504337
Micro-USB Power Supply for Charging the Lithium-Ion Battery
8029254
Micro B to A USB Cable for PC Communication/Charging
8101864
Eartip Assortment BET55
8104678
Package of Probe Tubes
8104159
Instructions for Use
country specific
Cavity (0.2/0.5 cc)
8011356
Plug for Hook cavity
8504384
OtoReadTM PC software package
8505352
Accessories included only in Standard and Clinical version
Item Number
Carrying Case
8004645
Cradle
8504302
Hook
8504385
Optional Components
Item Number
Carrying Case
8030335
Cradle
8504302
Hook
8504385
MPT-II Printer
8029304
Printer Power Supply for Charging Printer
8031231
Serial printer cable MPT-II
8011310
Thermal Printer Paper Roll
8029305
Neckstrap
8011481
1.6 Warnings
Throughout this manual the following definitions of warnings and cautions are used:
The WARNING label identifies conditions or practices that may present danger
to the patient and/or user.
The CAUTION label identifies conditions or practices that could result in
damage to the equipment.
1Applied part according to IEC 60601-1
WARNING
CAUTION

OtoRead™ Instructions for Use - US Page 4

OtoRead™ Instructions for Use - US Page 5
2 Unpacking and installation
Unpacking and inspection
Check box and contents for damage
When the instrument is received please check the shipping box for rough handling and damage. If the box is
damaged it should be kept until the contents of the shipment have been checked mechanically and
electrically. If the instrument is faulty please contact your local distributor. Keep the shipping material for the
carrier’s inspection and any potential insurance claim.
Keep carton for future shipment
The OtoRead™ comes in its own shipping carton, which is specially designed for the OtoRead™. Please
keep this carton. It will be needed if the instrument has to be returned for service.
If service is required please contact your local distributor.
Reporting imperfections
Inspect before connection
Prior to connecting the product it should once more be inspected for damage. All of the cabinet and the
accessories should be checked visually for scratches and missing parts.
Report immediately any faults
Any missing part or malfunction should be reported immediately to the supplier of the instrument together
with the invoice, serial number, and a detailed report of the problem. In the shipping box you will find a
’Return Report’ where you can describe the problem.
Please use ‘Return Report’
Please realise that if the service engineer does not know what problem to look for he may not find it, so using
the Return Report, which can be found in the shipping box, will be of great help to us and is your best
guarantee that the correction of the problem will be to your satisfaction.
Storage
If you need to store the OtoRead™ for a period, please ensure it is stored under the conditions specified in
the section for technical specifications.

OtoRead™ Instructions for Use - US Page 6
Symbols
The following symbols can be found on the instrument:
Symbol
Explanation
Type B applied parts.
Patient applied parts that are not conductive and can be immediately
released from the patient.
WEEE (EU-directive).
This symbol indicates that when the end-user wishes to discard this product,
it must be sent to separate collection facilities for recovery and recycling.
Failing to do so may endanger the environment.
0123
The CE-mark indicates that Interacoustics A/S meets the requirements of
Annex II of the Medical Device Directive 93/42/EEC.
TÜV Product Service, Identification No. 0123, has approved the quality
system.
Date of manufacture.
Manufacturer.
Do not re-use.
Parts like ear tips and similar are for single use only.
Underwriters Laboratories, Inc. label
MEDICAL-GENERAL MEDICAL EQUIPMENT
AS TO ELECTRICAL SHOCK, FIRE AND MECHANICAL HAZARDS ONLY
IN ACCORDANCE WITH ANSI/AAMI ES 60601-1 (2005) + AMD (2012)
CAN/CSA-C22.2 No. 60601-1 (2008) + (2014)
Serial Number.
Reference Number.
Global Trade Item Number.
Logo.
FCC marking with ID.
The instrument includes a RF transmitter.
DC- Direct current.
China RoHS label. Indicates that the product does not contain toxic and
hazardous substances or elements above the maximum concentration
values, and that it is an environmentally-friendly product which can be
recycled and reused.

OtoRead™ Instructions for Use - US Page 7
Keep Dry.
Transport and Storage Temperature range.
Transport and Storage Humidity limitations.
Transport and Storage Atmospheric pressure limitations.
General warnings and precautions
The following safety precautions must be observed at all times. General safety precautions must be followed
when operating electrical equipment. Failure to observe these precautions could result in damage to the
equipment and injury to the operator or patient.
The employer should instruct each employee in the recognition and avoidance of unsafe conditions and the
regulations applicable to his or her work environment to control or eliminate any hazards or other exposure to
illness or injury.
It is understood that safety rules within individual organizations vary. If a conflict exists between the material
contained in this manual and the rules of the organization using this instrument, the more stringent rules
should take precedence.
Read the entire instructions for use before attempting to use the system!
If the system is not functioning properly, do not operate it until all necessary repairs have been completed
and the unit has been tested and calibrated for proper functioning in accordance with Interacoustics
published specifications.
Do not drop or otherwise cause undue impact to this device. If the instrument is dropped or otherwise
damaged, return it to the manufacturer for repair and/or calibration. Do not use the instrument if any damage
is suspected.
This product and its components will perform reliably only when operated and maintained in accordance with
the instructions contained in this manual, accompanying labels, and/or inserts. A defective product should
not be used. Make sure all connections to external accessories are snug and secured properly. Parts which
may be broken or missing or are visibly worn, distorted, or contaminated should be replaced immediately
with clean, genuine replacement parts manufactured by or available from Interacoustics.
Equipment is not user repairable. Repairs must be performed by an authorized service representative only.
No conications of the equipment are allowed by anyone other than a qualified Interacoustics representative.
Modification of the equipment could be hazardous.
Interacoustics will make available on request: circuit diagrams, component part lists, descriptions, calibration
instructions, or other information that will assist authorized service personnel to repair those parts of this
instrument that are designated by Interacoustics as repairable by service personnel.
CAUTION

OtoRead™ Instructions for Use - US Page 8
No parts of the equipment can be serviced or maintained while in use with the patient.
Connect only accessories purchased from Interacoustics to the OtoReadTM. Only accessories which have
been stated by Interacoustics to be compatible are allowed to be connected to the device or cradle.
This equipment is intended to be connected to other equipment thus forming a Medical Electrical System.
External equipment intended for connection to signal input, signal output or other connectors shall comply
with the relevant product standard e.g. IEC 60950-1 for IT equipment (ITE) and the IEC 60601-series for
medical electrical equipment. In addition, all such combinations – Medical Electrical Systems – shall comply
with the safety requirements stated the general standard IEC 60601-1, edition 3, clause 16. Any equipment
not complying with the leakage current requirements in IEC 60601-1 shall be kept outside the patient
environment i.e. at least 1.5 m from the patient support or shall be supplied via a separation device to reduce
the leakage currents. Any person who connects external equipment to signal input, signal output or other
connectors has formed a Medical Electrical System and is therefore responsible for the system to comply
with the requirements. If in doubt, contact a qualified medical technician or your local representative. If the
instrument is connect to a PC (IT equipment forming a system) do not to touch the patient while operating
the PC.
If the instrument is connected to a PC (IT equipment forming a system), assembly and modifications shall be
evaluated by a qualified medical technician according to safety regulations in IEC 60601.
Please note: The USB connection on the instrument has an insulation protection on the cable. To prevent
potential leakage of electrical current to the patient, it is recommended that only the cable supplied is used.
The instrument is not protected against harmful ingress of water or other liquids. If any spillage occurs check
the instrument carefully before use or return for service.
No part of the equipment can be serviced or maintained while in use with the patient.
This instrument contains a lithium battery. The battery can only be changed by service personnel. Batteries
may explode or cause burns, if disassembled, crushed or exposed to fire or high temperatures. Do not short-
circuit. Please also refer to section 2.6.2.2.
Environmental factors
Use and store the instrument indoors only. Itisrecommended that the
instrument be operated within an ambient temperature range of 0 °C / -32 °F to
50 °C/ 122 °F and inrelative humidity of between 30 %and 90 %(non-
condensing).
Transport and store the instrument in temperatures between -20 °C / -4 °F 1 to
+50 °C / +122 °F and in relative humidity of between 10%and 95 % (non-
condensing).
Do not use the device in the presence of fluid that can come into contact with any of the electronic
components or wiring. Should the user suspect fluids have been in contact with the system components or
accessories, the unit should not be used until deemed safe by an authorized service technician.
CAUTION
WARNING

OtoRead™ Instructions for Use - US Page 9
Electrical and electrostatic safety
Before performing any service to the insert earphones you must detach
the OtoReadTM transducers from the patient.
Electromagnetic compatibility (EMC)
Although the instrument fulfills the relevant EMC requirements, precautions
should be taken to avoid unnecessary exposure to electromagnetic fields, e.g.,
from mobile phones etc. If the device is used adjacent to other equipment it
must be checked that no mutual disturbance appears. Please also refer to the
appendix regarding EMC.
Explosion hazards
Risk of explosion.
Do not use in the presence of flammable anesthetics or other gases.
Do NOT use in the presence of flammable gaseous mixtures. Users should
consider the possibility of explosions or fire when using this device in close
proximity to flammable anesthetic gases.
Do NOT use the OtoReadTM in a highly oxygen-enriched environment, such as
a hyperbaric chamber, oxygen tent, etc.
Measuring security
To guarantee that the OtoReadTM works properly, the instrument should be checked and calibrated at least
once per year.
The service and calibration must be performed by an authorized service technician. If these checks are not
done, EU Medical Device Directive (MDD) and other regulations may be violated and warranties may be
void.
The use of non-calibrated devices can lead to incorrect test results and is not advisable.
Miscellaneous
Please note:
DO NOT connect the OtoReadTM hardware to the computer before the software has been installed!
Do not place the instrument next to a heat source of any kind.
Great care should be exercised when handling transducers, as rough handling, for example dropping
onto a hard surface, may break or damage the parts.
Within the European Union it is illegal to dispose of electrical and electronic waste as
unsorted municipal waste. Electrical and electronic waste may contain hazardous
substances and therefore have to be disposed of separately. Such products will be marked
with the crossed-out wheelie-bin image shown to the left. User cooperation is important in
order to ensure a high level of reuse and recycling of electrical and electronic waste. Failure
to recycle such waste products in an appropriate way may endanger the environment and
consequently the health of human beings.
Outside the European Union, local regulations should be followed when disposing of the product after its
useful life.
CAUTION
CAUTION
WARNING

OtoRead™ Instructions for Use - US Page 10
Use of equipment after transport and storage
Please make sure the instrument is functioning correctly before use by running a test on a normal hearing
subject. If the instrument has been stored in a colder environment (even for a short period of time) please
allow the instrument to become acclimatized. This can take a long time depending on the conditions (eg
environmental humidity). You can reduce the condensation by storing the instrument in its original
packaging. If the instrument is stored under warmer conditions than normal, no special precaution are
required before use. Always ensure proper operation of the instrument by following routine check procedures
for audiometric equipment.

OtoRead™ Instructions for Use - US Page 11
Installing the cradle
Connect the Type B USB plug of the power supply to
the rear of the cradle (1).
USE ONLY UE08WCP-050160SPA POWER
SUPPLY.
The separable mains connector for UE08WCP-
050160SPA is used to safely disconnect mains from
the device. Do not position the power supply in a
position so that it is difficult to disconnect the device.
Do not attempt to use any other power supply. It could
cause risk of fire or electrical shock to operator or
patient
Place the cradle upright on your desk. There are
insertion guides to place the instrument properly into
the cradle.
Two pins can be found on the bottom of the
instrument bay to guide the OtoReadTM into place (2).
A USB plug will guarantee a proper connection via the
USB cable (3) .
Place the OtoReadTM into the cradle so that it sits
within the U-shaped placement guides. Proper
placement in the cradle is needed to ensure charging
of the battery.
Grasp the upper portion of the OtoReadTM above the
cradle placement guides and lift it out of the cradle.
WARNING
1
2
3
e

OtoRead™ Instructions for Use - US Page 12
Installing the Sanibel MPT-II printer (optional)
The OtoReadTM communicates with the MPT-II using a wireless connection protocol. Use only the
recommended label printer from provided with the equipment.
Battery charging
The label printer is powered by a Lithium-ion battery. Connect the power charger to the outlet on the left
hand side of the printer. The blue light on the top of the printer will indicate that charging is occurring. In
order to charge the battery you must insert the plug of the charger into the laterally placed socket and plug
the power supply into a power outlet.
Installing the MPT-II printer
1. Open the lid by pushing on the sides, insert paper roll as shown, and
close the lid.
2. Insert the battery.
Switching the printer on and off
Push POWER BUTTON for two seconds in order to power ON or
OFF. One short beep will be heard at power ON, two short beeps at
power OFF.
The green power indicator will be lit if the printer is powered by battery.
Light indicators
Green LED Indicator Blue LED Indicator Status Sound Note
Off
Fast Flash
Charging
-
Power ON
Off
On
Charging
-
Power OFF
Off Slow Flash Battery nearly
discharged
- -
Off
On
Charging completed
-
Power ON
Off
Off
Charging completed
-
Power OFF
On
Off
Power ON, battery
Beep
-
Slow flash
Slow flash
Out of paper
Beep
-
Slow flash
Off
Sleep mode
-
-

OtoRead™ Instructions for Use - US Page 13
Using the printer
Printer self-test:
While printer is powered OFF, press and hold PAPER FEED button, then press and hold POWER
BUTTON simultaneously. When beep is heard after approx. 3 seconds, release both buttons, and a
test page will print with information on current status and character samples.
Paper feed:
When powered, press PAPER FEED button. Paper will feed as long as the button is pressed.
Wireless setup:
Pairing with the instrument is necessary before wireless printing is possible.
Pairing process:
•Power on printer
•Let the instrument / PC search for other wireless devices
•A device called MPT-II should appear in the list of devices
•When prompted enter password “1234”
•Finish pairing
Note: Do not have several printers powered on and within range while searching.
It is possible to pair up to 8 instruments with one printer. If more instruments are paired, the oldest will be
deleted.
The hardware
The OtoReadTM test instrument
The OtoReadTM consists of the instrument, Micro-Probe, single-use
ear tips, replaceable probe tube and other accessories.
The OtoReadTM contains the hardware and software for generating
the test stimuli, measuring and displaying the OAEs, and storing the
results until they are printed.
The plastic housing contains circuit boards that provide the signal
processing and display the test results. The instrument also contains
a rechargeable lithium-ion battery to power the device. On the top of
the device, a probe holder (1) can be found, to ensure safe storage of
the probe.
The instrument uses an organic light-emitting diode (OLED) display
screen (2) and three light-emitting diodes (LEDs) (3) to provide a
visual display of test status to the operator. Four membrane-type
push buttons (4) located on the keypad of the device allow the user to
control testing and printing, and to reset test protocols.
1
2
3
4

OtoRead™ Instructions for Use - US Page 14
The probe houses a microphone and two speaker tubes which
produce test stimuli and measure the sound pressure level (SPL)
present in the sealed ear canal. Interface of the instrument to the ear
canal is accomplished through disposable ear tips made of industrial
elastomer which fit onto the probe tip. The disposable ear tips are
color coded to facilitate easy selection by size.
Charging and powering the OtoReadTM
2.6.2.1 The battery
The OtoReadTM instrument is powered by an integrated rechargeable lithium-ion battery (1800 mAh)
providing 20 hours (500 tests, minimum) of operation between full charging.
The battery can be charged in two ways:
1. While placed in the powered cradle.
2. When connected via USB cable to the PC or to the provided mains adapter.
Please note that the battery life will vary depending on each product configurationand that the maximum
capacity of this battery will decrease with time and usage. To prolong the battery life, do not completely
deplete the battery, but charge when 5 %-10 % of the battery remains.
The Micro-USB port on the bottom of the instrument is used for
charging via the power supply.
The blue battery indicator provides a visual indication (blue) of the
battery recharging function and battery status during operation.