The Marsden M-550 is a Class III, medical floor scale designed for accurate patient weight measurement in clinical and home care settings. It is commonly included in patient home kits and used alongside the Patient Facing app to capture and submit patient weight readings.
Device Specs
Maximum capacity: Model dependent, up to 200 kg (440 lbs)
Units of measure: Kilograms
Stabilization time: Approximately 1–2 seconds
Display: LCD with stable weight indicator
Power source: 4 x AA batteries
Auto power-off engages after inactivity to preserve battery life
A low battery indicator appears on the display when batteries need replacement
Replace all batteries at the same time when low battery is indicated
Panel Navigation
ON/OFF
Press this key to switch on the scale. The display will show 0.0kg.
Pressing the ON/OFF key on the opposite side of the display will reverse the scale’s display, therefore the display can be viewed by the patient.
If the scale shows a figure other than 0.0kg with no weight applied, press the ON/OFF key once to zero the display.
Press and hold the ON/OFF key to switch off the scale. 5. The ON/OFF key can also be used as the minus (-) key in BMI mode to reduce the height reading
HOLD
Press the HOLD/BMI key to enter into enable the Hold feature.
The arrow pointing at the hold symbol will start to flash and the LCD display will show.
The person being weighed can now stand on the scale. Their weight reading will hold and remain on the display.
To return the display back to zero, the HOLD/BMI button can either be pressed or the individual being weighed can step off the scale.
TARE
The ZERO/TARE key can be used to remove any unwanted weight from the scale’s display. For example, you may want to remove the weight of someone’s shoes from the reading, to leave only the person’s weight showing. To do this, place the shoes on the scale and press the ZERO/TARE key once. The weight of the shoes will then be zeroed off.
Weigh the individual as normal.
Remove the shoes and press ZERO/TARE again to cancel the Tare value and return the scale to zero.
BMI
After the patient stands on the scale, press and hold the HOLD/BMI key for three seconds. The scale will enter BMI mode.
The display will show the last inputted height.
Press the HOLD/BMI button to decrease the height and ZERO/TARE to increase the height.
When the correct height is showing on the display, press the ON/OFF button.
BMI will automatically be calculated and the display will show weight and BMI in rotation.
Press ON/OFF to disable the BMI function.
Setup
Insert four AA batteries into the battery compartment on the underside of the scale
Place the scale on a firm, level surface
Ensure all four scale feet are securely attached and stable
Confirm the display activates when stepped on
Submitting a Reading
Open the Patient Facing app on the tablet
Begin a weight task from the To Do List or use the 'New Reading' button to initiate the weight task
Wake the scale by stepping on briefly and stepping off
Step back onto the scale and stand still
Movement during this process may prevent the reading from being successfully transmitted, even if a number appears on the scale display.
Remain on the scale until the tablet screen confirms the reading has been captured
Tap on 'Submit' to return to the To Do List
Troubleshooting
Scale Errors
Error | Cause | Solution |
| Battery power is too low for normal operation.
| Replace all four AA batteries with new alkaline batteries, then retry. |
| The scale could not obtain a stable reading, often due to movement or an uneven surface.
| Place the scale on a hard, level floor, power it off, then retry once the display returns to zero. |
| The load sensor signal is too high, typically due to excessive weight or force.
| Remove all weight and power cycle the scale. If the error reappears with no load, remove the scale from use. |
| The load sensor signal is too low, usually because the scale is not fully supported on the floor.
| Ensure all four feet are flat on a stable surface, power the scale off, then turn it back on and retry. |
| The scale is above its zero range because weight is still being applied during startup.
| Remove all weight from the scale, power it off, then turn it back on and wait for the display to zero before use. |
| The scale is below its zero range due to an obstruction or pressure under the scale.
| Check underneath the scale for any obstruction, place it on a flat surface, then power it off and back on. |
| An internal processing or memory error has occurred.
| Power cycle the scale. If the error persists, remove the scale from use. |
Task Errors
Usage:
It is important to ensure the patient is utilizing the scale properly. Should the app display this error, confirm the patient understands proper protocols:
Sorry, we couldn't use that reading. After turning the scales on, step back slowly back on and stand very still for at least 10 seconds. Tap Retry and we'll try again
Ensure the scale is placed on a hard, level surface
Avoid carpeted or uneven flooring
Must be used indoors and in dry environments only
Confirm patient's expected weight is within scale's usable range (200kg/440lb maximum)
Ensure the patient remains still during the measurement
Confirm batteries are installed correctly and have sufficient charge
Replace batteries if the display is dim, unstable, or shows a low battery indicator
Connectivity:
It is important to ensure the scale is connected to the tablet. Should the app display this error, troubleshoot using the necessary steps:
Sorry we couldn't find your scales. Make sure the scales are turned on and in the same room as the tablet. Tap Retry and we'll keep looking.
Confirm the scale and tablet running the Patient Facing app are in the same room
Power cycle the scale by stepping on and off or allowing it to auto shut off before retrying
Ensure the correct scale is assigned to the patient’s kit in Dashboard
The tablet scans for, and connects to the scale via its 'MAC Address' that is located on the underside of the scale. The format will be ten alphanumeric characters in one of two formats: ########## OR ##:##:##:##:##
Ensure Bluetooth is enabled on the scale
Press and hold the ZERO/TARE button for 3 seconds until “SETUP” appears
Press and hold HOLD/BMI until “BLUET” is displayed
Press ZERO/TARE to enter Bluetooth settings
Use HOLD/BMI to toggle Bluetooth on or off
Press ZERO/TARE to confirm
Press HOLD/BMI twice, then ZERO/TARE once to return to weighing mode
Attempt reading once more
Additional Information
Clean using alcohol-based or approved disinfectant wipes only
Avoid excessive moisture, corrosive liquids, or high-pressure cleaning