
USER MANUAL
M-545
Please take time to read these
instructions before starting
to use the scale

Contents
Introduction 3
Product Specification 3
Safety Instructions 4
Explanation of Graphic Symbols 5
Power Supply and Low Battery 6
Installing Batteries 6
Operation: Basic Functions 7
Operation: Advanced Functions 9
ROHS Compliance 12
EMC Guidance and Manufacturer’s Declaration 13
Recommended Separation Distance 15
Error Messages 16
Manufacturer’s Declaration of Conformity 19

Thank you for purchasing a Marsden professional medical scale. This is a
precision Class III Weighing Instrument and considerate use will result in
many years of accurate weighing.
The scale has a maximum load capacity of 250kg which must not be
exceeded.
Product Specification
ON/ZERO/OFF, UNIT, SEND, HOLD/BMI,
TARE/BSA
6x 1.5V AA batteries or
12V 1A adaptor (UE24WCP1 – 120100SPA)
3cm display with 5 active digits
Base: 310mm x 310mm x 83mm
Indicator: 174mm x 107.6mm x 50mm

Safety Instructions
Before putting the device into use, please read with care the information given in this user manual,
which contains important instructions for proper installation, use and maintenance of the device.
Marsden/the manufacturer shall not be liable for damages arising from failure to heed the following
instructions:
When using electrical components under increased safety requirements, always comply with
appropriate regulations.
Inappropriate installation/use will render the warranty null and void.
Ensure the voltage marked on the power supply unit matches your mains supply.
This device is designed for use indoors.
Observe the permissible ambient temperatures for use.
The device meets the requirements for electromagnetic capability. Do not exceed the
maximum values specified in the applicable standards.
Batteries should be kept away from small children. If swallowed, promptly seek medical
assistance.
If you have any problems, contact Marsden/your local dealer/your service partner.
Cleaning
We recommend using alcohol-based wipes or similar when cleaning the scale.
Please do not use corrosive liquids, large amounts of water or high pressure washers.
Always disconnect the scale from the mains power supply before cleaning.
Maintenance
The scale does not require any routine maintenance. However, we recommend checking the
scale’s accuracy at regular intervals. If any inaccuracies occur, please contact your local dealer
or service partner.
Marsden can provide service contracts for your weighing scales. For more information about
Marsden service contracts call 01709 364296.
Disposing of the Scale
This product should not be treated as regular household waste, but should be handed in to an
electrical/electronic equipment recycling centre.
You can obtain further details from your local council, your municipal waste disposal company
or from where you purchased the product.

Explanation of Graphic Symbols
Designation of the serial number of
every device, applied to the device.
(Number as an example)
“Please note the accompanying
documents” or “Observe operating
instructions”
Charder Electronic Co. Ltd
No.103 Guozhong Rd, Dali Dist,
Taichung City 412, Taiwan (R.O.C)
Identification of manufacturer of
medical product including address.
Dispose of old appliances separately
from your household waste.
This product must be disposed of at a
communal collection point.
Carefully read this operation manual
before setup and commissioning, even if
you are already familiar with Marsden
scales.
Transport and storage temperature limit
indicating the upper and lower limit
(transport and storage temperature on
packaging).

Power Supply & Low Battery
The indicator uses power from 6x AA batteries, or can be powered from the mains via the adaptor.
Make sure the batteries are installed in the battery box of the indicator. Alternatively, plug the adaptor
(12V 1A) into the port on the side of the scale.
Installing Batteries
Remove the battery cover.
Remove the battery case and insert
batteries, ensuring they are properly
installed.
Install the battery housing.

Operation: Basic Functions
Switching on the Scale
Press the ON/ZERO/OFF button firmly.
When the scale shows 0.0 on the display
you are ready to start weighing.
Hold the ON/ZERO/OFF button for three
seconds when the scale is turned on. The
scale will power down.

Setting the Scale to Zero
If the display shows a reading other than
0.0 when nothing is on the scale, it can be
reset to zero.
Press ON/ZERO/OFF once.
The scale will return to 0.0.

Operation: Advanced Functions
Hold Function
Press the HOLD/BMI button once, either
whilst the patient is stood on the scale or
before they step onto the scale.
After a few seconds the scale will lock on
the person’s weight. When the patient
leaves the scale, the weight will remain on
the display.
Press HOLD/BMI again to disable the Hold
function and return the scale to 0.0.
Note: If the weight reading remains on the display for more than five minutes, the Hold
function will automatically disable and the display will return to 0.0. If another patient
steps on the scale whilst a held weight reading is being displayed, the Hold function
will be disabled.

Body Mass Index (BMI) Function
The patient should first stand on the scale.
Hold down the HOLD/BMI button to enter
BMI mode. The scale will enter height
setting mode and the extreme left digit
will flash.
Enter the height by using the TARE/BSA
button to decrease the value and
HOLD/BMI button to increase the value. To
move to the next digit, press SEND.
To confirm the height hold down the
ON/ZERO/OFF button, after a few seconds
the display will alternate between weight,
height and BMI.
To exit BMI mode and return to normal
weighing mode, hold down the HOLD/BMI
button.

After calculating BMI, you can then
calculate BSA. After going through the
first four steps on the previous page
steps to calculate BMI, press TARE/BSA
and Body Surface Area will be
displayed.
Place the item/s you wish to deduct
from the reading (such as a pair of
shoes) on the scale and press
TARE/BSA.
Remove the item/s, and the scale will
show a minus reading.
Weigh the patient as normal and the
negative weight reading will be
deducted from the total weight.

ROHS Compliance
EU Directive 2011/65/EU restrict the use of the 6 substances below in the manufacture of
specified types of electrical equipment.
The product does not contain any of the restricted substances in concentrations and
applications banned by the directive;
and for components, the product is capable of being worked on at higher
temperatures required by lead-free soldering.
The restricted substances and maximum allowed concentrations in the homogenous
material are, by weight:
PBB (Polybrominated Biphenyls)
PBDE (Polybrominated Diphenyl Ethers)
Transmission Specification

EMC Guidance and Manufacturer’s Declaration
Guidance and manufacturer’s declaration - electromagnetic emissions.
The M-545 is intended for use in the electromagnetic environment specified below. The
customer or user of this scale should assure that it is used in such an environment.
Electromagnetic environmentguidance
This scale uses RF energy only for
its internal function. Therefore, its
RF emissions are very low and not
likely to cause any interference in
nearby electronic equipment.
This scale is suitable for use in all
establishments, including domestic
establishments and those directly
connected to the public lowvoltage power supply network that
supplies buildings used for
domestic purposes.
Harmonic emissions
IEC 61000-3-2
Voltage fluctuations/flicker
emissions
IEC 61000-3-3
Guidance and manufacturer’s declaration – electromagnetic immunity.
The M-545 is intended for use in the electromagnetic environment specified below. The customer or the user
of this scale should ensure that it is used in such an environment.
Electromagnetic environment-
guidance
Electrostatic discharge(ESD)
IEC 61000-4-2
± 6 kV contact
± 8 kV air
± 6 kV contact
± 8 kV air
Floors should be wood, concrete or
ceramic tile. If floors are covered
with synthetic material, the relative
humidity should be at least 30%
Electrical fast transient/burst
IEC 61000-4-4
± 2kV for power
supply lines + 1kV
for input/output
lines
± 2kV for power
supply lines Not
applicable
Mains power quality should be that
of a typical commercial or hospital
environment.
± 1kV line(s) to
line(s) ± 2kV line(s)
to earth
± 1kV differential
mode Not
applicable
Mains power quality should be that
of a typical commercial or hospital
environment.

Guidance and manufacturer’s declaration – electromagnetic immunity.
This scale is intended for use in the electromagnetic environment specified below. The customer or the user
of the scale should ensure that it is used in such an environment.
Electromagnetic environmentguidance
Voltage Dips, short
interruptions and voltage
variations on power
supply input lines IEC
61000-4-11
<5% UT(>95% dip in
UT) for 0,5 cycle 40%
UT(60% dip in UT) for
5 cycles 70% UT(30%
dip in UT) for 25
cycles <5% UT(>95%
dip in UT) for 5 s
<5% UT(>95% dip in
UT) for 0,5 cycle 40%
UT(60% dip in UT) for 5
cycles 70% UT(30% dip
in UT) for 25 cycles
<5% UT(>95% dip in
UT) for 5 s
Mains power quality should be that of a
typical commercial or hospital
environment. If the M-545 requires
continued operation during power mains
interruptions, it is recommended that the
M-545 be powered from an uninterruptible
power supply or a battery.
Power frequency(50/60
Hz) magnetic field IEC
61000-4-8
The M-545 power frequency magnetic
fields should be at levels characteristic of a
typical location in a typical commercial or
hospital environment.
NOTE UT is the AC mains voltage prior to application of the test level.
Guidance and manufacturer’s declaration-electromagnetic immunity.
The M-545 is intended for use in the electromagnetic environment specified below. The customer or the user
of the scale should assure that is used in such an environment.
Electromagnetic
environment-guidance
Conducted RF
IEC 61000-4-6
Radiated RF IEC
61000-4-3
3 Vrms
150 KHz to 80 MHz
3 V/m 80MHz to 2,5 GHz
Portable and mobile RF
communications equipment should be
used no closer to any part of the M-
545 including cables, than the
recommended separation distance
calculated from the equation applicable
to the frequency of the transmitter.
Recommended separation distance:
d = 1,2 √
P
d = 1,2 √
P
80MHz to 800 MHz
d = 2,3 √
P
800MHz to 2,5 GHz
Where P is the maximum output power
rating of the transmitter in watts (W)
according to the transmitter
manufacturer and d is the
recommended separation distance in
metres (m).
Field strengths from fixed RF
transmitters, as determined by an
electromagnetic site surveya, should be
less than the compliance level in each
frequency rangeb.
Interference may occur in the vicinity of
equipment marked with the following
symbol:
NOTE1 At 80 MHz and 800 MHz, the higher frequency range applies.
NOTE2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by
absorption and reflection from structures, objects and people.

a Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and
land mobile radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted
theoretically with accuracy. To assess the electromagnetic environment due to fixed RF transmitters, an
electromagnetic site survey should be considered.
b Over the frequency range 150 kHz to 80 MHz, field strengths should be les than 3 V/m.
Recommended separation distance between portable and mobile RF communications
equipment and the M-545.
Rated maximum output
power of transmitter
W
Separation distance according to frequency of transmitter m
150 kHz to 80 MHz
d = 1,2√
P
80 MHz to 800 MHz
d = 1,2√P
800 MHz to 2,5 GHz
d = 2,3√P
For transmitters rated at a maximum output power not listed above, the recommended separation distance d
in meters (m) can be estimated using the equation applicable to the frequency of the transmitter, where p is
the maximum output rating of the transmitter in watts (w) according to the transmitter manufacturer.
NOTE1) At 80 MHz and 800 MHz, the separation distance for the high frequency range applies.
NOTE2) These guidelines may not apply in all situations. Electromagnetic propagation is affected by
absorption and reflection from structures, objects and people.

Low Battery
The scale’s AA type batteries are flat; please
replace the batteries.
Overload
This indicates that the scale’s load sensor(s)
have been overloaded. Reduce the loading
and retry.
Counting Error
1. The signal from the load cells is too
high or too low. Please remove any
weight from the scale, switch the
scale off and power on again. If the
scale continues to show this message,
it indicates a fault with the electronics
or wiring.
High/Low Zero Count
1. The scale is above its zero range.
Please remove any weight from the
scale and power on again. If the scale
continues to show the error message,
it indicates a fault with the
electronics.
2. The scale is below its zero range.
Check there is nothing jammed
underneath the scale and power on
again. If the scale continues to show
the error message, it indicates a fault
with the electronics.
AD Error
This indicates there is a fault with the scale’s
software and is normally caused by a fault
with the PC board. Contact your local
service representative.
Negative weighing
The weight reading is below -2kg. Press
ZERO to return to 0.0.

Manufacturer’s Declaration of Conformity
This product has been manufactured in accordance with the harmonized European
standards, following the provisions of the below stated directives:

Tel: 01709 364296 / 0800 169 2775
Fax: 01709 364293
E-mail: sales@marsdengroup.co.uk
Manufacturing and Distribution:
Unit 7, Centurion Business Park,
Coggin Mill Way,
Rotherham,
S60 1FB
Head Office:
Unit 1, Genesis Business Park,
Sheffield Road,
Rotherham
S60 1DX
www.marsden-weighing.co.uk
IN-1254 (IN-8498) [80001H] REV 03/2017