Welch Allyn MicroTymp 3 User manual

MicroTymp®3 Handle and

MicroTymp® Printer/Charger

Service manual

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

© 2009 Welch Allyn. All rights are reserved. No one is permitted to reproduce or duplicate, in any form, this manual or any part thereof without written permission from Welch Allyn.

Welch Allyn assumes no responsibility for any injury to anyone, or for any illegal or improper use of the product, that may result from failure to use this product in accordance with the instructions, precautions, warnings, or statement of intended use published in this manual.

Welch Allyn and MicroTymp are registered trademarks of Welch Allyn.

XP is trademark of Microsoft.

Software in this product is copyrighted by Welch Allyn or its vendors. All rights are reserved. The software is protected by United States of America copyright laws and international treaty provisions applicable worldwide. Under such laws, the licensee is entitled to use the copy of the software incorporated with this instrument as intended in the operation of the product in which it is embedded. The software may not be copied, decompiled, reverse-engineered, disassembled or otherwise reduced to human-perceivable form. This is not a sale of the software or any copy of the software; all right, title and ownership of the software remain with Welch Allyn or its vendors.

For information about any Welch Allyn product, call the nearest Welch Allyn representative:

	USA		+ 1 315 685 4560			Australia	+ 61 2 9638 3000
			800 535 6663
	Canada		800 561 8797			China	+ 86 216 327 9631
	European Call Center		+ 35 3 46 906 7790			France	+ 33 1 60 09 33 66
	Germany		+ 49 7477 92 71 86			Japan	+ 81 3 3219 0071
	Latin America		+ 1 305 669 9003			Netherlands	+ 31 15 750 5000
	Singapore		+ 65 6419 8100			South Africa	+ 27 11 777 7555
	United Kingdom		+ 44 20 7365 6780			Sweden	+ 46 8 58 53 65 51
	REF	406695
Material No. 714876 Ver. A
				Welch Allyn, Ltd.
Welch Allyn, Inc.				Navan Business Park
4341 State Street Road				Dublin Road, Navan
Skaneateles Falls, NY 13153 -0220 USA				County Meath, Republic of Ireland

www.welchallyn.com

iii

Contents

1 - Introduction and technical overview . . . . . . . . . . . . . . . . . . . . . . . . . 1

About this document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Intended use. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 About the device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Supporting documents and definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Definitions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Technical overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Controls, indicators, and connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Handle components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Printer/Charger components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 General warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 General cautions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 General notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

2 - Testing and verification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Bench test and calibration check - Handle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Purpose of test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Preparation for test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Bench test procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Final Tester Setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Testing Performed by the ATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Bench test for the Printer/Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Proper powering up of unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Proper operation of print head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Agency tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Dielectric strength test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Grounding continuity test. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Leakage current test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3 - Troubleshooting guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Handle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Printer/Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Noise troubleshooting procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Leak troubleshooting procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Error and service code tables with troubleshooting procedure . . . . . . . . . . . . . 33

Error codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Retrieving and clearing error codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Service codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

4 - Disassembly and reassembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Handle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Disassembly Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

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Contents

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Removal/replacement of the LCD and keypad board assemblies . . . . . . . . 42 Removal/replacement of the power PCBA. . . . . . . . . . . . . . . . . . . . . . . . . . 43 Removal/replacement of the MCU PCBA . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Replacement of Lithium coin battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Proper placement of ESD shields in the back housing. . . . . . . . . . . . . . . . . 45

Printer/Charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Removal/replacement of the top panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Removal/replacement of the main PC board and print head assemblies. . . 47 Removal/replacement of the contact housing and IR flex assemblies. . . . . 48 Removal/replacement of the printer keyboard/LEDs assembly . . . . . . . . . . 49 Removal/replacement of the RFI filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Removal/replacement of old main PC board and print head . . . . . . . . . . . . 50

A - Repair parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 B - Cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Clean the handle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Clean the printer/charger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Clean the probe tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

C - Replacement parts and accessories . . . . . . . . . . . . . . . . . . . . . . . . 57

1

1 Introduction and technical overview

About this document

This document is written for technical professionals who are qualified to service medical instruments. The intended technical environment is any location where service on such devices is performed. This document describes how to test, calibrate, diagnose, disassemble, and assemble the MicroTymp3 Handle and MicroTymp Printer/Charger.

Before attempting service on the tympanometer, you must read and understand this document and all other information that accompanies the tympanometer and its accessories.

Intended use

This device is an auditory impedance tester intended to detect possible otologic disorders associated with the functioning of the middle ear.

About the device

Federal US law restricts sale of the device identified in this manual to, or on the order of, a licensed physician.

Using this device’s 226-Hz and 1000-Hz tympanometry settings, you can quickly and easily obtain objective results supporting diagnosis of otitis media with effusion and other middle ear disorders. This information can result in more thorough diagnoses as well as more effective monitoring, treatment, consultation, and referral.

The 226-Hz test data stored in the memory of the Handle may be printed using the Printer/Charger. The Printer/Charger reads the information from the Handle and prints out tympanograms and interpretation.

Note The Handle also provides the ability to test patients utilizing a 1000-Hz frequency mode. This mode features a quick interpretation result that displays a Pass, Refer, or Retest message on the LCD (see Chapter 4 of the DFU, part number 714694). Results from the quick interpretation mode can be documented using the 1000Hz screening results card. Results from the 1000-Hz quick interpretation mode will not print.

The switch to change the default frequency is located on the top of the power supply PC board. The table on the next page gives the function choices of this switch pack.

2	Introduction and technical overview	Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger
	Switch State	Function
	Switch 1 off	1000 Hz
	Switch 1 on	226 Hz
	Switch 2 off	Platform communication
	Switch 2 on	Printer communication
	Switches 3 and 4	Not used

The Printer/Charger also charges the rechargeable battery in the Handle.

For more detailed operating instructions, see the DFU for the MicroTymp3 Handle, part number 714694.

Supporting documents and definitions

•Manufacturing Test Specifications for MicroTymp 2.5, DIR number 60029314

•DID for MicroTymp 2.5, DIR number 60029426

•MicroTymp3 Directions for Use, DIR number 80015401

•MicroTymp Hardware Technical Specifications, DIR number 60030837

•How2 - MicroTymp 2.5 MPS, DIR number 70020334

Definitions

ATE	Automated Test Equipment
cc	Cubic centimeter, a unit of volume
daPa	Decapascal, the unit of air pressure used for tympanometric
	measurements, 1 daPa = 1.04 mm H20
EEPROM	Electrically Erasable Programmable Read-Only Memory
LUT	Look Up Table
mbar	Unit of atmospheric air pressure measurement
mmho	Acoustic millimho, the unit of acoustic admittance
MCU PCA	Micro controller Unit Printed Circuit Board Assembly
PS PCA	Power Supply Printed Circuit Board Assembly
USB	Universal Serial Bus
UUT	Unit Under Test
Vea	Volume of ear canal
WACP	Welch Allyn Communications Protocol

Service manual

Introduction and technical overview

3

Technical overview

The Handle hardware contains the necessary circuitry to perform, measure, and report tympanograms. It is designed to be portable and rechargeable, and to interface with its corresponding printer device.

In order to perform a tympanogram, the hardware must support a motor/pump assembly that is capable of a positive and negative pressure in the ear canal. Simultaneously, a speaker must drive a monotonic 226-Hz, 85 dB sound pressure into the ear. A microphone amplifier and A/D converter are included to monitor this sound pressure. The control of the system (tone and pressure), and display of the tympanogram are implemented with two micro controllers. The hardware and software must provide a closed-loop system that maintains the 85 dB sound pressure, regardless of the acoustical admittance in the ear that changes with pressure.

In addition, the Handle shall be capable of performing fully the above function with a 1000-Hz, 83 dB tone.

In order to support the operator interface, the hardware supports an LCD and keypad with three keys. In order to interface with the Printer/Charger, the Handle has an IR sensor communication interface. The Handle is designed to start by the press of a button, or by insertion into the printer/charger unit.

The Handle hardware system is broken down at the top level into three board-level assemblies:

1)The MCU Board

2)The Power Supply Board

3)The LCD Board

There are other integral components such as the sensors, motor/pump assembly, switches, USB port, and IR interface which play significant roles in the plotting of the tympanogram, the powering up of the unit, and the communication of the unit with a service computer, ATE testing station, or Printer/Charger.

The Power Supply Board can be broken down into these subsystems:

1.The keypad/power up logic is responsible to start the power supply and interrupt the master MCU whenever a key is depressed. It also reports which key is depressed and receives an input from the MCU to keep the system powered up.

2.The battery charger provides a constant current charge to the battery whenever the Handle is in a printer base. When the battery voltage reaches 4.2 volts, the charger shall cease charging the battery.

3.The battery detection reports a low battery warning to the micro controller.

4.The negative power supply is an inverting switched capacitor power supply used to support the analog circuitry and the LCD display.

5.The pump motor control provides a selectable voltage to the motor in either forward or reverse polarity.

6.The pump motor home detect determines whether the pump diaphragm is above or below the home position.

7.The valve control provides a fixed voltage to the valve in either the open or closed polarity.

4

Introduction and technical overview

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

The MCU Board can be broken down into these subsystems:

1.The master micro controller is directly responsible for the sound pressure control loop, operator interface, IR communication, USB communication, and power control.

2.The slave micro controller is directly responsible for the motor control, valve control, and pressure amplifier.

3.The IR communication is a bidirectional link between the Handle and Printer/Charger base.

4.The USB port is a bidirectional link between the Handle and either the ATE or the service computer.

5.The speaker drive provides a 226-Hz sine wave to the speaker. The amplitude is adjusted by the master MCU to control the sound compliance loop. Digital calibration is also provided for speaker gain and system cavity size differences. These same processes also apply to the 1000-Hz function of the Handle.

6.The microphone sends its signal to the A/D converter before filtering. This is true for both the 226-Hz and 1000-Hz signals.

7.The ADC digitizes the output of the microphone amplifier to be used by the master MCU in the compliance control loop. Digital calibration of the microphone gain is also performed.

8.The pressure amplifier scales the signal from the pressure transducer and provides it to the slave MCU. Digital calibration for transducer gain and offset are provided.

Service manual

Introduction and technical overview

5

Controls, indicators, and connectors

Handle components

Tip

Probe

Tip ejector

Battery cover

Side view	Front view
			1.0					2 GR
		mmho						A	Veacc
			0.5					1
		Ya-						C	+200
								GR
			0
			-400 -200 0				200
				PRESSURE - daPa

TEST

	3®MicroTymp Tympanometric Portable
	Instrument
	0297
C	US
74227
Patent Pending US Pat #5,383,097
IEC TYPE 3 ANSI TYPE 4		REF
Skaneateles Falls, NY USA		23650

Liquid Crystal

Display (LCD)

Left memory button

Test button

Right memory button

Infrared data transfer window

Bottom view

Micro-USB

NOTE: Reserved for future use

Lithium-ion battery

Interior view

	ON
	ON CTS
-	1 2 3 4
REF	OFF
72910
Ion Lithium +	ON
	ON CTS

Handle switches

6

Introduction and technical overview

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Printer/Charger components

Charging well for MicroTymp 2 or 3

Card holder with 1000-Hz screening results cards

CHARGE				FEED button
indicator

PRINT button

	Tip box				POWER
					indicator

IEC power cord receptacle

Printer/Charger switches

Paper access	Paper
cover	slot

Power Cord

To power

To IEC power

receptacle

cord receptacle

Service manual

Introduction and technical overview

7

Symbols

Documentation symbols

Warning

(Warnings indicate conditions or practices that could lead to illness, injury, or death.)

Consult instructions for use

Caution

(Cautions indicate conditions or practices that could damage the equipment or other property)

Hot surface

Operation symbols

	POWER indicator	FEED button
	CHARGE indicator	PRINT button
	TEST button	RIGHT memory button
TEST		R
GR	Gradient width adult	LEFT memory button
		L
A
GR	Gradient width child	Switch options ON/OFF symbol
C
Shipping, storing, and environment symbols
+49ºC	Temperature limits	95% Relative humidity limit
-20ºC
	This end up	Recycle

Recycle the product separate from other disposables. See www.welchallyn.com/ weee for collection point and additional information.

Separate batteries from other disposables for recycling.

Power and connectivity symbols

Lithium-ion

8

Introduction and technical overview

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Certification symbols

Meets essential requirements of European Medical Device Directive 93/42/EEC

Complies with applicable U.S. and Canadian medical safety standards

0297		74227
	Class I equipment, Type BF			European regulatory manager
	(Handle)

Class I equipment, Type B (Printer/Charger)

Miscellaneous symbols

REF

SN

Reorder number

Manufacturer

Serial number

Service manual

Introduction and technical overview

9

General warnings

WARNING Explosion risk. Do not use Handle or Printer/Charger near flammable anesthetics.

WARNING Electric shock hazard. Do not attempt to disassemble the Printer/ Charger. Refer all servicing to Welch Allyn or a Welch Allyn authorized service representative.

WARNING Electric shock hazard. Use the USB connector only to connect to devices complying with IEC 60601-1 or other IEC standards as appropriate to the device. The user is responsible for verifying that the system complies with the requirements of the system standard IEC 60601-1-1 if additional devices are connected to the Handle.

WARNING Improper handling or disposal of the battery can lead to heat generation, smoke, bursting, or fire.

WARNING Do not disassemble, modify, or solder the battery.

WARNING Do not directly connect (short circuit) the positive (+) and negative (–) battery terminals.

WARNING To avoid short circuits, keep the battery terminals away from metal objects.

WARNING Do not dispose of the battery in fire.

WARNING Do not expose the battery to temperatures above 80°C (176°F).

WARNING Use only the specified charger to charge the battery.

General cautions

Caution Charge only Handle #23640, Handle #23650, or AudioScope 3 (#23300) in the Printer/Charger.

Caution If the device has not been stored within the operating temperature range, allow 24 hours minimum for it to return to operating temperature range (15-35°C or 59-95°F) before using.

10

Introduction and technical overview

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Caution Do not store either the Handle or Printer/Charger at temperatures below -20°C (-4°F) or above +49°C (120°F). Continual exposure to extremely low or high temperatures can permanently damage components.

Caution The battery must be removed if the Handle is to be stored or placed anywhere other than in the powered Printer/Charger for more than one month. Failure to do this can result in damage to the Handle.

Caution This instrument contains components which are static sensitive. Before touching any internal Handle component, be sure that you have discharged any static electricity by touching a grounded metal object.

Caution To prevent equipment damage, charge the Handle only with the

Printer/Charger (#7117x).

General notes

The Printer/Charger (#7117x) will charge and print data from the MicroTymp2 or MicroTymp3 Handle. However, the original Printer/Charger (#7113x) will neither charge nor print data from the MicroTymp3 Handle.

Please complete and return the warranty registration. It validates the warranty and allows Welch Allyn to communicate calibration notices and software changes.

11

2 Testing and verification

Tools

•Pressure applicator source with range of -400 to +300 daPa with 1 daPa resolution

•Variable voltage (0-10 VDC) output power supply with at least 500 mA capacity

•Test cavity set, part number T20015974. See picture below for sizes.

•Handle

•Printer/Charger

•Digital voltmeter 3 ½ digit

•Hemostat or crimping needle nose pliers

•Set screw key, size 0.035

•Nut driver size 5/32 inch or 4 mm, thin wall preferred

•Other nut driver sizes needed: 3/16 inch and 1/4 inch

•Small and medium size Philips screwdrivers

•ROHS (lead free) soldering iron and lead free solder

•Tweezers

•Stop watch for leak test

•Service computer (Windows XP®, or higher) with 'Sample Client,’ version June 25, 2009. This program will give control of the Handle during the bench test. For Sample Client to work On-Host Version 1.0.0 or equivalent must be installed prior to using the WACP Sample Application.

•USB cable (thin connector) for connection to service computer

•B&K sound level meter model 2250, with ½-inch microphone model 4192 and 2 cc coupler model 49461

•Barometric Pressure transducer, model 276 or equivalent (must measure pressure in mmHg)1

Pressure box (T-5657 or equivalent)

Test cavity set (T20015974)

1.These pieces are ATE. They are needed when the calibration is updated but not for the bench test.

12

Testing and verification

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

B&K sound level meter model 2250	1/2-inch microphone model 4192 and
	2 cc coupler model 4946

Off-the-shelf tools

Barometer

Service manual

Testing and verification

13

Bench test and calibration check - Handle

Purpose of test

To test for and detect problems in the following portions of the Handle:

1.Leak and vent rate

2.Noise (226 and 1000 Hz) and sweep rate test

3.Compliance check

For the purpose of detecting and repairing problems before the unit is run on the ATE. This will alleviate failures on the final ATE test. Therefore, these tests should be performed before final testing on the ATE.

Refer to the “Troubleshooting guide” starting on page 29 for solutions to the problems encountered during the bench and ATE tests.

Preparation for test

Note Use only the functions of sample client as set forth is this manual.

1.Open the sample client program on the service computer by navigating to the 'Sample Client' folder. Open it and click on the 'Sample App' folder. Double click on the 'Sample Client' file. Program will open. See opening screen picture.

2.Connect USB cable from Handle to service computer.

Note Any time a new battery is installed it is necessary to connect the MicroTymp handle to the USB cable or insert it into the printer/charger for five seconds before powering up the handle. (This enables the battery protection circuit).

Sample client location

14

Testing and verification

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

3. Select the choices as shown in the picture below: 1 for start, 1 for number of connections, and 2 for USB.

Opening screen

4.An extensive menu should display on the service computer screen. Making sure that the Handle is powered on, select the number of the 'Disable Power Timeout,' selection number 20. This will enable the Handle to stay powered up throughout the test.

Sample client menu

Bench test procedures

Test 1 - Leak and vent tests

1.With the main menu still showing on the service computer screen, select number 12, FmTYMP Test. The FmTYMP Test screen will show. Select number 3, Send command. Select number 14, Set Valve. Select number 1 to close valve. An audible click will be heard indicating the valve has been latched closed. Unit can now be tested for leaks.

2.Connect pressure box to the probe tip of the Handle. Throw select switch on pressure box to positive position and pressure/vent switch to pressure position.

Service manual

Testing and verification

15

3.Adjust box to 300 daPa, let it sit for about ten seconds, and then observe the leak rate. It must be less than 10 daPa in five seconds.

4.Vent the unit by throwing the pressure/vent switch on the box to vent position (V).

5.Put select switch in negative position and pressure/vent switch to pressure position.

6.Adjust pressure to -400 (meter will read +400), wait ten seconds, and then observe leak rate. It must be less than 10 daPa in five seconds.

7.Readjust pressure to -400 daPa.

8.Open valve on Handle by selecting number 2, Open Valve, on the service computer. Pressure should drop to zero in two seconds or less.

9.To re-enable the timeout circuit, simultaneously press/release all three buttons on Handle. Unit will power down. Power up unit and confirm that unit powers down in about fifteen seconds.

Test 2 - Noise and sweep rate tests

1.Set the unit to 226 Hz.

2.Put a 0.2 cc cavity on the probe tip. Hold unit upright and take a reading.

3.There should be a straight line across the bottom. Ideally, there should be no pixels above the base line. If there are pixels one row above that is acceptable. Any pixels two rows or more above the base line constitutes a failure. See pictures at the end of this section.

4.Take four tympanograms and make sure all readings are a pass.

5.In addition, note the sweep across the bottom of the screen during a tympanogram. It should move at an even speed. Make sure there is no notable slowdown or sudden start/stops.

6.Repeat steps 2 through 5 for the 2.0 cc cavity.

7.Set the unit to 1000 Hz.

Note The cavity test for 1000 Hz will show the correct volume but not a straight line across the bottom of the LCD. The line may be slightly elevated but no higher than 0.4 mmho. It is important that the correct volume is displayed. A REFER message will also appear on the LCD, and it does not indicate a problem.

8. Perform cavity tests for 1000 Hz with the 0.2 and 2.0 cc cavities.

1000 Hz Typmanogram

Volume of tested cavity

16

Testing and verification

Welch Allyn MicroTymp3 Handle and MicroTymp Printer/Charger

Good tympanogram (226 Hz)	Unacceptable tympanogram (226 Hz)

Test 3 - Compliance check for 226 Hz function only

1.Place a 0.5 cc cavity onto the probe tip. Make sure cavity fits properly. The rubber tip from the cavity should not be pulling away from the white tip ejector. See picture below.

2.Press the 'TEST' button on the Handle. The unit should take a reading as a flat line across the bottom of the screen. Press the 'L' button to store the reading into the left memory. Observe the 'LEFT STORE' message.

3.Insert Handle into Printer/Charger and print out results. The Vea reading should be 0.5 cc +/- 0.1 cc.

4.Repeat steps 1 through 3 with a 1.5 and a 2.4 cc cavity, but press the 'R' button to store the readings into the right memory. The Vea reading should be the cavity size +/- 0.1 cc.

Properly applied test cavity

Printout of test tympanogram

No gap shown

Volume reading

Unit is now ready for final test on the ATE.

Note All units must be tested on the ATE before shipment to the customer.