Welch Allyn 52000 Series User manual

Service Manual
Vital Signs Monitor
(52000 Series)
Protocol QuikSigns
(52000 Series)
Welch Allyn, Inc.
4341 State Street Road
P.O. Box 220
Skaneateles Falls, NY 13153-0220
95P445E Rev. C Copyright 1999
This manual covers the Enhanced Vital Signs Monitor introduced
in June 1999. The Enchanced VSM is easily detected by a dark
blue "Silence" button on the front panel instead of a grey button.

Revision Information
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor i
Revision History
Drawings and/or illustrations and/or part numbers in this document are for refer-
ence only. For the most current revision call the Welch Allyn Customer Service
phone number listed in Section 1.
Date ECN# Revision Description Originator Approval
06/10/1999 A Introduction of Service Manual JDB JDB
10/06/03 5-46657 B Correction made to
temperature accuracy, part
numbers, error codes and
updates to the drawings.
Revised to meet Service
Manual Work Instructions.
JDB, DLK DLK
12/12/03 5-46990 C Revised service and support
details in Section 1 and
Appendix E. Re-formatted
units of measurement to meet
NIST Standards. Corrected
grammar and punctuation.
Added page numbering to
blank pages.
DLK RJS

ii Welch Allyn Vital Signs Monitor Service Manual 95P445E Rev. C

Table Of Contents
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor iii
Section 1: General Information
To Service Personnel...................................................................................................... 1
Intent of Manual and Product Scope ............................................................................. 1
Limited Warranty.......................................................................................................... 2
Owner Maintenance...................................................................................................... 2
Warranty, Service, and Spare Parts................................................................................ 2
Periodic Calibration Requirements ................................................................................ 3
Incoming Inspection ...................................................................................................... 4
Introduction .................................................................................................................. 5
Basic System Operation ................................................................................................. 5
Specifications............................................................................................................... 10
Mechanical Specifications............................................................................................ 12
Electrical Specifications ............................................................................................... 13
Environmental Specifications....................................................................................... 13
Identification Label and Serial Numbering System Defined ......................................... 14
Firmware Identification ............................................................................................... 14
Section 2: Calibration/Service
Tools required for Service............................................................................................ 15
Test Equipment Bench Layout..................................................................................... 16
Voltage Calibration ..................................................................................................... 17
Pressure Calibration .................................................................................................... 17
Loading Unit Software................................................................................................. 18
Section 3: Troubleshooting
Diagnostic Procedure for Returned Units..................................................................... 19
Battery Voltage Check................................................................................................. 19
LED Functional Check ................................................................................................ 19
BP Functional Check ................................................................................................... 19
Printer Functional Check............................................................................................. 20
SpO
2
Functional Check ............................................................................................... 20
Temperature Functional Check.................................................................................... 20
Communication Functional Check .............................................................................. 20
Calibration Tests ......................................................................................................... 21
Current Tests............................................................................................................... 22
Noise Levels ................................................................................................................ 22
Button Test.................................................................................................................. 22
Print Quality............................................................................................................... 23
Pneumatic Tests........................................................................................................... 23
Fail Safe Testing .......................................................................................................... 24
SpO
2
Tests................................................................................................................... 25
Temperature Tests....................................................................................................... 26
Nurse Call Testing....................................................................................................... 26
Self Diagnostic Fault Codes ......................................................................................... 27
Main Board/Blood Pressure Error Codes ..................................................................... 27
SpO
2
Error Codes........................................................................................................ 27

Table Of Contents
iv Welch Allyn Vital Signs Monitor Service Manual 95P445E Rev. C
Temperature Error Codes............................................................................................ 28
Temperature Error Code Correction............................................................................ 28
Complaint / Cause / Corrective Action ........................................................................ 29
Section 4 Disassembly/Assembly
Front Housing ............................................................................................................. 33
Main PCB.................................................................................................................... 34
DC to DC Converter (SpO
2
Units Only)...................................................................... 36
Pressure Transducers on Main PCB ............................................................................. 38
Display PCB Removal.................................................................................................. 40
Key Pad (Switch Array) ............................................................................................... 42
Temperature PCB ........................................................................................................ 44
Specific Oxygen Board (Nonin SpO
2
PCB).................................................................. 46
Specific Oxygen Board (Nellcor SpO
2
PCB - MP205 or MP506)................................. 48
Pump/Motor Assembly................................................................................................ 50
Valve (Pneutronics)...................................................................................................... 52
Printer/Printer PCB/Keypad ......................................................................................... 54
Battery Placement........................................................................................................ 56
Appendix A: Repair Parts List
Repair Parts List........................................................................................................... 57
Appendix B: Product Structure/Accessories
Product Structure/Accessories ....................................................................................... 63
Appendix C: Assembly Drawings/Board layout
Assembly Drawings/Board Layout................................................................................ 69
Appendix D: Repair Test Specifications
Repair Tests Specifications ........................................................................................... 75
Unit Manometer Calibration ....................................................................................... 76
Manometer Accuracy Test........................................................................................... 76
Deflation Test.............................................................................................................. 77
Voltage Testing............................................................................................................ 77
Unit Current Tests....................................................................................................... 77
Noise Tes..................................................................................................................... 77
Hardware Fail-safe Tests ............................................................................................. 77
SpO
2
Tests................................................................................................................... 78
Temperature Option Testing ....................................................................................... 79
Printer Option Testing................................................................................................. 79
RS232 Testing ............................................................................................................. 79
RS423 Testing (Acuity Monitors)................................................................................ 79
Appendix E: Check List For Service Work
Check List for Service Work ......................................................................................... 83

List of Tables and Figures
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor v
List Of Tables
Table 2-1. Tools required for calibration and repair of the Vital Signs Monitor. ......... 15
Table 3-1. Button press response table.......................................................................... 25
Table 3-2. Main board/blood pressure error code table............................................... 29
Table 3-3. SpO
2
error code table................................................................................. 27
Table 3-4. Temperature error code table. .................................................................... 28
Table 3-5. General Guide to Problems and Corrective Actions. ................................... 29
List Of Figures
Figure 1-1. Nurse call interface diagram...................................................................... 10
Figure 1-2. Serial number label.................................................................................... 14
Figure 2-1. Bench layout for re-calibration and testing of the Vital Signs Monitor. ..... 16
Figure 4-1. DC to DC replacement. ............................................................................. 37
Figure 4-2. Pressure transducer replacement............................................................... . 39
Figure 4-3. RTV removal from NONIN SpO
2
PCB..................................................... 47
Figure 4-4. SpO
2
jack, wire side .................................................................................. 47
Figure 4-5. Bottom view of valve (Pneutronics). .......................................................... 53

vi Welch Allyn Vital Signs Monitor Service Manual 95P445E Rev. C

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 1
To Service Personnel
Read and understand the Vital Signs Monitor Operator's Manual and this service manual.
The information contained in these publications are subject to change without notice and
should not be construed as a commitment by Welch Allyn, Inc.
Welch Allyn assumes no responsibility for any errors that may appear in this manual. If the
product and/or its operation varies significantly from any description herein, please contact
the following:
Welch Allyn, Inc.
1-800-535-6663
315-685-4100
Fax [phone]
Welch Allyn, Inc.
4341 State Street Road
Skaneateles Falls, NY 13153
This product has been designed to provide a high degree of safety and reliability. However,
we can not guarantee against: deterioration of components due to aging, normal wear,
tampering, and abuse.
Only Authorized Welch Allyn personnel or agents must perform all service and repairs,
using approved Welch Allyn replacement parts and approved process materials. Failure to
follow these guidelines will invalidate the product warranty. Please refer to the product
warranty for specific coverage.
Intent of Manual and Product Scope
This manual provides technical service and re-calibration information to technicians
authorized to repair and re calibrate Welch Allyn, Inc. products. When used in conjunction
with the required test equipment and tools, technicians will be able to diagnose, repair, and
re-calibrate, and test the Vital Signs Monitor.
The manual includes: Re-calibration instructions, fault/cause analysis, step-by-step
disassembly and re-assembly procedures, repair, adjustment, and re-test procedures.

2 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
Limited Warranty
Welch Allyn, Inc. warrants the Vital Signs Monitor, when new, to be free of defects in
material and workmanship and to perform in accordance with manufacturer's
specifications for a period of two years from the date of purchase from Welch Allyn, Inc.
or its authorized distributors or agents. Accessories (battery, cuff, tubing, temperature
probe, SpO
2
sensor and transformer) carry a one-year warranty. Welch Allyn, Inc. will
either repair or replace any components found to be defective or at variance from
manufacturer's specifications within this time at no cost to the customer. It shall be the
purchaser's responsibility to return the instrument to Welch Allyn, Inc. or an authorized
distributor, agent or service representative. This warranty does not include breakage or
failure due to tampering, misuse, neglect, accidents, modification or shipping. This
warranty is also void if the instrument is not used in accordance with manufacturer's
recommendations or if repaired by other than Welch Allyn, Inc. or an authorized agent.
Purchase date determines warranty requirements. No other express warranty is given.
To receive service assistance or to ask questions regarding this warranty, please call your
nearest Welch Allyn Technical Support Center.
Owner Maintenance
Owner Maintenance: Non-Technical customers can perform normal maintenance per the
instructions provided in the Operator's Manual. End users will be able to perform basic
operations such as replacement of: hoses, cuffs, probes, and batteries. On this level the unit
will not be opened (except for the battery housing). Opening of the Vital Signs Monitor by
untrained individuals will damage the unit and void the warranty.
Warranty, Service, and Spare Parts
Warranty Service
All repairs on products under warranty must be performed or approved by Welch Allyn.
Unauthorized repairs will void the warranty. In addition, whether or not covered under
warranty, any product repair shall exclusively be performed by Welch Allyn trained and
certified service personnel.
Assistance and Parts
If the product fails to function properly or if assistance, service, or spare parts are required,
contact the nearest Welch Allyn Technical Support Center.
USA 1-800-535-6663 Latin America ([phone]
European Call Center ([phone] United Kingdom 0-207-365-6780
France ([phone] Germany ([phone]
Canada 1-800-561-8797 South Africa ([phone]

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 3
Australia ([phone] Singapore ([phone]
Japan ([phone] China ([phone]
Before contacting Welch Allyn it is helpful to attempt to duplicate the problem and to
check all accessories to ensure that they are not the cause of the problem.
When calling, please be prepared to provide:
•The product name, model number and complete description of the problem
•The serial number of your product (if applicable)
•The complete name, address and phone number of your facility
•For out-of-warranty repairs or spare parts orders, a purchase order (or credit card)
number
•The required spare or replacement part number(s), for parts order
Repairs
If your product requires warranty, extended warranty, or non-warranty repair service,
please call first the nearest Welch Allyn Technical Support Center. A representative will
assist you in troubleshooting the problem and will make every effort to solve the problem
over the phone, avoiding potential unnecessary return.
In case the return cannot be avoided, the representative will record all necessary
information and will provide a Return Material Authorization (RMA) number, as well as
the appropriate return address.
A Return Material Authorization (RMA) number must be obtained prior to any return. Be
sure to note this number on the outside of your shipping box.
Packing Instructions
•If you have to return goods for service, follow these recommended packing instructions:
•Remove all hoses, cables, sensors, power cords, and ancillary products (as appropriate)
before packing, unless you suspect they are associated with the problem.
•Wherever possible use the original shipping carton and packing materials.
•Include a packing list and the Welch Allyn Return Material Authorization (RMA)
number.
•Be sure to note the (RMA) number on the outside of your shipping box.
It is recommended that all returned goods be insured. Claims for loss or damage to the
product must be initiated by the sender.
Periodic Calibration Requirements
Welch Allyn, Inc. recommends that the calibration of the Vital Signs Monitor be checked
on a yearly basis for BP, Temperature and SpO
2
(if applicable).

4 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
Incoming Inspection
NOTE: Use the following guidelines when unpacking the Vital Signs Monitor from its
shipping carton.
1. Before opening the Vital Signs Monitor shipping carton, check for damage.
2. If damage is apparent, stop unpacking the carton and contact the shipping company for
further instructions. If the carton is intact, unpack the Vital Signs Monitor.
3. With the Vital Signs Monitor out of its carton, check to see that all the items listed on
the packing slip are included.
4. If an item is missing, first check the carton, then check with your receiving department.
If necessary contact your nearest Welch Allyn representative.
5. Clean and disinfect by following the instructions printed in the Operator’s Manual.
Note: Perform all functional tests as listed in Section 3 before and after servicing. Operate
the Vital Signs Monitor to verify the customer complaint before making any changes to the
unit. Call the customer if the complaint is unclear.
If the unit has caused or is suspected of having caused an injury of any type: DO NOT
DISASSEMBLE OR REPAIR THE UNIT IN ANY WAY. Contact your nearest Welch
Allyn Customer Support Center immediately.

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 5
Introduction
The Welch Allyn Vital Signs Monitor, also marketed as QuickSigns, is designed to non-
invasively and automatically measure systolic and diastolic pressure, pulse rate,
temperature and oxygen saturation (SpO
2
) for adult and pediatric patients. THE WELCH
ALLYN VITAL SIGNS MONITOR IS NOT TO BE USED ON NEONATAL PATIENTS.
All blood pressure, pulse, temperature and SpO
2
values can be viewed on a large, easy-to-
read display, and may be printed via the integrated printer as desired.
The rechargeable lead acid battery and variety of mounting accessories make the Welch
Allyn Vital Signs Monitor convenient for many locations. The operator may choose any
combination of simultaneous measurement modalities. This flexibility, combined with
features such as programmable alarms and automatic BP cycles, makes the Welch Allyn
Vital Signs Monitor ideal for a wide variety of patient monitoring needs.
Refer to the Welch Allyn Vital Signs Monitor Operator’s Manual for complete information
on Indications For Use, Special Features, Supplies and Accessories.
Basic System Operation
Blood Pressure Operating Modes
When a blood pressure measurement cycle is initiated, the cuff will automatically inflate to
the default pressure level.
The cuff will immediately begin to deflate in a stepped fashion and will determine systolic
pressure and diastolic pressure from the pulses sensed by the cuff at various pressure levels.
This is the oscillometric method of non-invasive blood pressure monitoring.
Blood pressure measurements may be initiated manually, or automatically at time intervals
determined by the user.
At the completion of a measurement cycle the systolic and diastolic pressures are displayed.
If the Monitor is in Automatic Mode, the measured values are kept on display until the
next BP measurement is initiated. When not in Automatic Mode, the measured values are
displayed for two minutes, after which time the display screen is blanked. The most recent
BP measurement may be recalled by pressing the REVIEW button.
When in Automatic Mode, if the unit is unable to determine the systolic or diastolic value,
the measurement will be automatically repeated once.
Blood Pressure Manual Mode
In the Manual Mode, a single blood pressure determination is made only when the START
button is pushed. The manual mode is the default mode of operation for blood pressure
determinations.
A measurement cycle may be cancelled at any time by pressing the CANCEL button. This
action immediately initiates a rapid cuff deflation.

6 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
The blood pressure measurement data will appear on the display immediately following
the measurement. The display will blank after two minutes. If the display is blank, pressing
the REVIEW button on the front panel will recall the measurement. Up to 99 prior
measurements are available for review or printing.
In Blood Pressure Manual Mode, the following alarm limits may be activated; SYSTOLIC
HIGH LIMIT, SYSTOLIC LOW LIMIT, DIASTOLIC HIGH LIMIT, DIASTOLIC LOW
LIMIT, PULSE RATE HIGH LIMIT and PULSE RATE LOW LIMIT. Blood pressure
determinations, which activate alarms, are indicated by flashing displays and a repetitive
audible tone. If an alarm limit is violated, subsequent blood pressure determinations may
be made only after the alarm condition is reset by pressing any button on the Monitor's
display.
Blood Pressure Automatic Mode
The Automatic Blood Pressure Mode is entered by pressing the AUTO button. Pressing the
AUTO button displays a choice of 11 cycle interval times as follows: "St" (STAT mode), 1
minute, 3 minutes, 4 minutes, 5 minutes, 10 minutes, 15 minutes, 30 minutes, 45 minutes,
60 minutes and 90 minutes. These choices represent the time interval from the beginning of
one cycle to the beginning of the next automatic cycle. STAT mode allows the monitor to
take continuous blood pressure measurements for 15 minutes. In addition, the operator
may choose to disable the Auto Mode by choosing “--” (two dashes).
Note: In the 1-minute automatic cycle mode, the Welch Allyn Vital Signs Monitor will
automatically take blood pressure measurements in 1-minute intervals for up to 15
minutes.
A measurement cycle may be cancelled at any time by pressing the CANCEL button. This
action immediately initiates a rapid cuff deflation.
The blood pressure measurement data will appear on the display immediately following
the measurement and will remain displayed until the next measurement cycle is initiated.
In Blood Pressure Auto Mode, the following alarm limits may be activated; SYSTOLIC
HIGH LIMIT, SYSTOLIC LOW LIMIT, DIASTOLIC HIGH LIMIT, DIASTOLIC LOW
LIMIT, PULSE RATE HIGH LIMIT and PULSE RATE LOW LIMIT. Blood pressure
determinations, which activate alarms, are indicated by flashing displays and a repetitive
audible tone. Any alarm limit violation must be reset to continue automatically timed
blood pressure determinations. The alarm may be reset by pressing any button on the
Monitor's display.
Temperature Operating Modes
Thermometry measurements are made with the integrated Welch Allyn SureTemp
TM
thermometer. Oral and rectal probes utilize single-use disposable probe covers which limit
cross-contamination. Oral, axillary or rectal temperatures are taken using Normal or
Monitor operating modes. Axillary temperatures are taken using the oral probe.

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 7
In Normal mode the thermometer's microprocessor "predicts" body temperature in about
4 seconds for oral temperatures, about 10 seconds for axillary temperatures and in about
15 seconds for rectal temperatures. The Monitor mode displays the patient's actual
temperature after 3 minutes for oral/rectal mode and 5 minutes for axillary mode, and will
continue to display an updated temperature as long as the probe remains in place.
Note: Normal mode axillary temperatures (10 seconds) are accurate only for children
under the age of four.
Note: The Welch Allyn Vital Signs Monitor is not intended to be used on Neonatal
patients.
Temperature readings may be displayed in Fahrenheit or Celsius scales.
Temperature Normal Mode
In Normal mode, the device will measure temperature at discrete intervals and then
calculate the rate of change according to a proven algorithm. This allows the thermometer
to predict the end point that the thermistor would reach if it were left in the mouth until it
reached mouth temperature. This predictive feature allows the thermometer to arrive at an
accurate oral temperature reading in approximately 4 seconds.
Normal mode is the default operating mode for temperature determinations.
Operator selectable patient alarm limits are not available in temperature Normal mode.
However, temperatures which are outside of the operating range of the device will be noted
on the temperature display.
Temperature Monitor Mode
Continuous Monitor mode operation is normally used for longer term monitoring and
when difficult situations prevent accurate temperatures from being taken in the Normal
mode. The probe must be in contact with tissue for at least three (3) minutes for accurate
oral/rectal temperature measurement and five (5) minutes for accurate axillary temperature
measurement. Monitor mode temperatures may not be identical to predicted 'Normal'
temperatures because of ambient temperature influence and other factors. The trend in
temperature is the important standard to be observed when in the Monitor mode.
Operator selectable patient alarm limits are not available in temperature Monitor mode.
However, temperatures which are outside of the normal operating range of the device will
be noted on the temperature display.
SpO
2
Operating Mode
The Welch Allyn Vital Signs Monitor incorporates the Nellcor Puritan Bennett
TM
pulse
oximetry module which determines arterial oxyhemoglobin saturation (SpO
2
%) by
measuring the absorption of red and infrared light passed through the tissues. Changes in
absorption caused by pulsation of blood in the vascular bed are used to determine arterial
saturation and pulse rate.

8 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
Oxygen saturation percent is calculated with each pulse detected, and thus the monitor
display is continually updated. The pulse signal bar graph is an indicator of the strength
and quality of the detected pulses.
When SpO
2
is measured, the patient's pulse rate is also measured and displayed. A pulse
rate measurement from the SpO
2
determination overrides a pulse rate measurement
derived from a blood pressure measurement.
When measuring SpO
2
the user may enable the SpO
2
Pulse Tone feature. A short audible
tone is emitted with every patient heartbeat. The frequency of the tone is based on the
patient’s SpO
2
level. The lower the frequency of the tone, the lower the patients SpO
2
level.
In SpO
2
monitoring mode, operator selectable alarm limits for low SpO
2
% may be
activated. A condition which violates the SpO
2
low limit alarm is indicated by a flashing
display and repetitive audible tone. Should a patient alarm condition for SpO
2
or pulse rate
occur, the Monitor will indicate an alarm condition (flashing & beeping) while continuing
to monitor and display the patient's current SpO
2
%. The alarm will automatically reset
when the patient's condition returns to within the preset alarm parameters.
Should a patient alarm condition for SpO
2
or pulse rate occur, the operator may invoke
"Silence Mode" by pressing the SILENCE button. This will silence the audible tone
(display will continue to flash), while the practitioner attends to the patient and the
monitor. Silence mode resets automatically after 30 seconds, or when the patient's
condition returns to within the preset alarm parameters.
Removal of the SpO
2
sensor from the patient will initiate an alarm, unless the SpO
2
and
pulse rate alarms are turned off. To reset the sensor alarm, press any button on the
Monitor's display.
SpO
2
is generally measured via pulses detected using a finger sensor. However, for certain
situations SpO
2
may be measured at alternate sites including the earlobe, forehead and
toes. Special sensors must be employed in these situations.
SpO
2
Monitor Mode
The SpO
2
monitor performs most accurately with the fingerclip sensor, which may be used
on all fingers except the thumb. The finger clip sensor is recommended for spot checks or
short term continuous monitoring.
The device determines arterial oxyhemoglobin saturation (SpO
2
%) by measuring the
absorption of red and infrared light passed through the tissue. Oxygen saturation and
pulse rate are displayed on the LED digital display. On each detected pulse, the pulse signal
bar graph flashes. The intensity of this signal is a simple visual indicator of waveform
signal strength, and can identify situations where the pulsatile nature of the tissue may not
be adequate for an accurate SpO
2
reading. The update interval of the bar graph should
correspond to the patient's pulse rate. This is an indication of the quality of the SpO
2
signal.

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 9
All Welch Allyn Vital Signs Monitors with pulse oximetry capability are equipped with a
pulse tone. This audible tone beeps in synchronization with each beat of the patient’s heart.
In addition, the frequency of the tone will vary based on the patient’s oxygen saturation
value. The higher the tone’s frequency, the higher the patient’s oxygen saturation value.
The user may change the pulse tone volume, or turn this feature off as necessary.
Pulse Rate Feature
The Welch Allyn Vital Signs Monitor is capable of determining pulse rate as an adjunct to
the blood pressure measurement and the SpO
2
measurement.
The pulse rate, in beats per minute, will be determined primarily from the SpO
2
measurement methodology. In the case where SpO
2
is not available, or is disabled, the
pulse rate display will be driven by data from the blood pressure measurement method.
There are two operator selectable alarm limits for the pulse rate. They are PULSE RATE
HIGH LIMIT and PULSE RATE LOW LIMIT. Pulse rates which activate alarm limits are
indicated by a flashing display and a repetitive audible tone.
Should a pulse rate alarm occur when the pulse rate measurement is derived from the
blood pressure measurement, no subsequent blood pressure or pulse rate measurements
may be made until the alarm is reset. The alarm may be reset by pressing any button on the
Monitor's display. Should a pulse rate alarm occur when the pulse rate measurement is
derived from the SpO
2
measurement, the monitor will indicate an alarm condition
(flashing & beeping) while continuing to monitor and display the patient's current SpO
2
%
and pulse rate. The alarm will automatically reset when the patient's condition returns to
within the preset alarm parameters.
Should a patient alarm condition for pulse rate occur during SpO
2
monitoring, the
operator may invoke "Silence Mode" by pressing the SILENCE button. This will silence
the audible tone (display will continue to flash), while the practitioner attends to the
patient and Monitor. Silence mode resets automatically after 30 seconds, or when the
patient's condition returns to within the preset alarm parameters. If an alarm limit is
violated, subsequent determinations of any type may only be made after the alarm
condition is reset.

10 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
NOTE: See Nurse Call Interface in the Operator’s Manual for complete information on
the Nurse Call interface.
Figure 1-1. Nurse call interface diagram.
The Welch Allyn Vital Signs Monitor provides a switch closure output between two pins of
the serial connector (pins 7 and 8). The output is universal in that it is compatible with a
wide variety of different systems with no polarity dependence. The Nurse Call output is
ohmically isolated from all circuitry.
The output is rated for 1 Amp at 240VAC or 30Vdc. During an alarm condition the output
is closed, otherwise the output is open. During a power off or power failure condition the
output is open.
Specifications
The performance specifications of the Vital Signs Monitor are as follows:
Patient Population
The Welch Allyn Vital Signs Monitor is designed for use with adult and pediatric patients.
Welch Allyn defines a pediatric patient as 29 days old and above. THE VITAL SIGNS
MONITOR IS NOT INTENDED FOR USE WITH NEONATES. Welch Allyn defines
neonates as children 28 days or less of age born at term (37 weeks gestation or more):
otherwise, up to 44 gestational weeks.
Cuff Pressure Range
0 mmHg - 300 mmHg
Initial Cuff Inflation
120, 140, 160, 180, 200, 240, 280 mmHg depending on pressure preset level. Pressure
preset default is 160 mmHg.
Contact Wires Normally Open
Nurse Call Common
TX Data
RX Data
DTR
Ground
1
6
2
7
3
8
4
9
5
Nurse Call Contacts:
30Vdc@1ampor
240Vac @ 1 amp
1
6
2
7
3
8
4
9
5
RS-232 DB-9
Vital Signs Monitor RS-232 Cable

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 11
Systolic Range
Maximum: 250 mmHg
Minimum: 60 mmHg
Diastolic Range
Maximum: 160 mmHg
Minimum: 30 mmHg
Blood Pressure Accuracy
Blood pressure accuracy meets or exceeds SP10-1992 AAMI standards for non-invasive
blood pressure accuracy (AAMI standard: ±5 mmHg mean error; 8 mmHg standard
deviation). Blood pressure accuracy is validated for pressure measurement using the upper
arm only, with the patient in a seated position. Blood pressure is validated against manual
auscultatory readings for adults and children above the age of 3. For children under age 3
blood pressures is validated against intraarterial readings. The monitor is not validated for
use with neonates.
Blood Pressure Determination Time
20 seconds to 45 seconds typical, 165 seconds maximum.
Pulse Rate Range (Using SpO
2
determination)
Maximum: 200bpm
Minimum: 40bpm
Pulse Rate Accuracy
SpO
2
Module Heart Rate (Nellcor Puritan Bennett)±3 bpm
Blood Pressure Algorithm Heart Rate ±5.0%
Overpressure Cutoff
295 mmHg to 330 mmHg
Temperature Ranges
Maximum – 108 °F (42.2 °C)
Minimum – 84.0 °F (28.9 °C)
Temperature Accuracy
Calibration Accuracy: ±0.2 °F (±0.1 °C)
Temperature Determination Time
(Oral) 4 seconds typical, 15 seconds maximum
(Axillary) 10 seconds typical
(Rectal) 15 seconds typical
Oxygen Saturation Range (SpO
2
%)
40-99% oxygen saturation

12 Welch Allyn Vital Signs Monitor Monitor Service Manual 95P445E Rev. C
Section 1 General Information
SpO
2
Accuracy
Nellcor MP205
±3% in the range of 70-100% oxygen saturation (1 Standard Deviation)
<70% unspecified by the OEM.
Nellcor MP506
Without Motion - Adults: 70 to 100% ± 2 digits*
With Motion - Adults: 70 to 100% ± 3 digits**
Low Perfusion: 70 to 100% ± 2 digits***
<70% unspecified by the OEM
Bio compatibility testing has been conducted on Nellcor sensors in compliance with
ISO10993-1, Biological Evaluation of Medical Devices, Part 1: Evaluation and Testing.
The sensors have passed the recommended bio compatibility testing and are therefore in
compliance with ISO 10993-1.
* Adult specifications are shown for OxiMax MAX-A sensors. Saturation accuracy will
vary by sensor type. Refer to the following Sensor Accuracy Grid.
**Applicability: OxiMax MAX-A, MAX-P, and MAX-I sensors.
*** Specification applies to monitor performance and was validated with Biotek and
Nellcor simulators.
Battery Charging (90%-100% capacity in 12 hours).
Unit will operate and charge battery simultaneously when connected to power source.
Mechanical Specifications
Dimensions
Height 6.5 inches (16.5 cm)
Length 8.6 inches (21.8 cm)
Depth 5.0 inches (12.7 cm)
Weight
Approximately 6 pounds (2.8 Kg)
Mounting
Self-supporting on rubber feet
Custom Mobile Stand
Custom Made Wall Mount
Custom IV pole mount
Attaches to bed rail

General Information Section 1
Service Manual 95P445E Rev. C Welch Allyn Vital Signs Monitor 13
Electrical Specifications
Power Requirements
Patient-Rated isolation transformer is connected to AC mains:
North American Version: 120 Vac, 60 Hz 0.20 A Input Source, 8 Vdc, 0.75 A Output
Source
International Version: 220-240 Vdc, 50-60 Hz 0.20A Input Source, 8 Vdc, 0.75 A Output
Source
Battery (Lead acid, with external charger)
A fully charged battery will support 200"typical" blood pressure determinations taken at 7
minute intervals. Battery is 90%-100% charged after 6-12 hours of charging. The battery
automatically charges when the Vital Signs monitor is powered through the AC power
transformer. The battery will charge faster when the instrument is not in operation.
Environmental Specifications
Operating Temperature
+10 °C to +40 °C (Except temperature 16 °C to 40 °C)
+50 °F to +104 °F
Storage Temperature
-20 °C to +50 °C
-4 °F to +122 °F
Relative Humidity
15% to 90% (non-condensing)
Operating Altitude
-170 m to +4877 m
-557 ft to +16,000 ft