Interacoustics AT235 Service Manual
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Interacoustics AT235 Service Manual

Impedance audiometer
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Science made smarter
Service Manual
AT235
Impedance Audiometer

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Summary of Contents for Interacoustics AT235

  • Page 1 Science made smarter Service Manual AT235 Impedance Audiometer...

  • Page 2: Table Of Contents

    Table of Contents Introduction ..............................1 About this manual ............................ 1 About warnings and cautions ........................1 General information ..........................1 Maintenance and Disassembly ........................2 General cleaning and maintenance procedure ..................2 Maintenance of the pump module ......................3 Disassembling the Cabinet ........................

  • Page 3: Introduction

    Introduction About this manual This manual is for our Impedance Audiometer AT235, firmware version 1.42. The contents of the manual cover instrument related data, such as disassembly, calibration, and pump module maintenance. Technical specifications, schematics, parts & accessories list along with the firmware update procedure can be found as appendices in the back of the manual.

  • Page 4: Maintenance And Disassembly

    Service Manual AT235 Maintenance and Disassembly General cleaning and maintenance procedure CAUTION • Before cleaning the device, always make sure that the device is switched off and disconnected from the power supply Use a soft cloth lightly dampened with cleaning solution to clean all exposed surfaces •...

  • Page 5: Maintenance Of The Pump Module

    AT235 Maintenance of the pump module This chapter contains a thorough introduction and guide to the AT235. Carried out by a technician authorized by Interacoustics, the most common action would be the pump module maintenance with the purpose of detecting any deterioration on the pump tube.
  • Page 6 Service Manual AT235 The panel can now be carefully removed by lifting The pump module which is attached to the access it up in the top end and releasing the bottom from panel can now be flipped over. Please note that it is its holder.
  • Page 7 Service Manual AT235 Remove the screw with an Unbrako key 1.5. Use a flat bladed screwdriver to carefully open the lock mechanism holding the wheel in place. Fig. 9 Fig. 10 Once unlocked, the wheel with the pump tube can be lifted up and off of the module.

  • Page 8: Disassembling The Cabinet

    Service Manual AT235 Disassembling the Cabinet To disassemble the instrument, the top must be The panels are now loose for dismantling the parts. separated from the bottom cabinet. The Be careful whilst separating as the parts are still cabinets are separated by removing the attached with cables on the inside.

  • Page 9: Mainboard

    Service Manual AT235 2.3.1 Mainboard This chapter describes how the mainboard is removed. The probe connection board is released by unfastening the indicated points: The white tube should be released at the indicated end and removed through the loops. The orange cable...

  • Page 10: Rotary Dial

    Service Manual AT235 2.3.2 Rotary dial For dismantling the rotary dial, remove the cover With a screwdriver, remove the 3 screws holding the by flipping it off. cover in place. Fig. 20 Fig. 21 Now, the 3 black screws holding the dial in place The rotary dial can now be removed from the top can also be removed with a screwdriver.

  • Page 11: Display

    Access to the SD card is possible when removing the panel and the screw holding it in place. We highly recommend use of SD card types authorized by Interacoustics, as we otherwise cannot guarantee safe storage of the data. NOTICE Replacement of the SD card protocol overwrites present data and user settings.

  • Page 12: Calibration Procedure

    Interacoustics. Before any attempt is made to calibrate AT235, it must have been powered on for 3-5 minutes in an ambient temperature that is both stable and comfortable.

  • Page 13: Equipment Requirements

    Service Manual AT235 Equipment requirements 3.2.1 Equipment requirements for impedance calibrations To ensure proper calibration of audiometric equipment, test instruments must be reliable, stable and their calibration certified. The minimum requirements for measuring equipment are: 1) A measuring amplifier with input for condenser microphone or a sound level meter, fulfilling Type 1 of the IEC 60651 requirements.

  • Page 14: Calibration Of Test Equipment

    Connection between the instrument and a computer, should be conducted as described in Installing the Diagnostic Suite.The calibration program is activated by starting the program and following the on-screen instructions. The program is found via the below path: C:\Program Files (x86)\Interacoustics\Diagnostic Suite\CalibrationAD629AC40AT235.exe...

  • Page 15: Checklist For Calibration

    Service Manual AT235 3.3.2 Checklist for calibration Use this list to ensure no aspect of the calibration is forgotten. MECHANICAL INSPECTION PASS / FAIL Plug - verify that plugs appear intact and undamaged Cables - verify that the cable insulation appears intact Display - verify that display is intact and undamaged.

  • Page 16: Installing The Diagnostic Suite

    Installing the Diagnostic Suite The Diagnostic Suite is available in the USB stick. However, the free Diagnostics Suite upgrade package and the Diagnostic Calibration Tools are available from the Interacoustics extranet. The upgrade package enables upgrade from previous versions of the software.
  • Page 17 Fig. 31 The driver has now been successfully installed and the AT235 is ready for connection to the computer. NOTICE: Using operating systems where Microsoft have discontinued software and security support will increase the risk of viruses and malware, which may result in breakdowns, data loss and data theft and misuse.

  • Page 18: Main Startup

    Service Manual AT235 Main startup C:\Program Files (x86)\Interacoustics\Diagnostic Suite\ Select CalibrationAD629AC40AT235.exe The startup screen should look as below with the Connect button highlighted to indicate correct connection. If the Connect button is fully highlighted, the instrument is not properly connected. In this case shut down the application, open it and Connect again.

  • Page 19: Saving The Calibration Data

    Service Manual AT235 Saving the calibration data There are two ways of saving the calibration data in the programme, and the only difference between the two is that method 1 is easier and ensures a continuous “saving flow”, should the computer or the equipment shut down in an untimely manner, for instance caused by a power outage.
  • Page 20 Service Manual AT235 Method 2. After a given action, go to the Main menu and select ‘Write to hardware’ as illustrated below. A dialog box with the message Calibration data successfully written to hardware pops up when the action is successfully completed.

  • Page 21: Calibration Of Transducers

    Service Manual AT235 Calibration of Transducers Calibration standard for Impedance 4.1.1 Transducer setup Select Transducer setup to upload the calibration values to the contra phone connected to the device. NOTICE Switching between different transducers requires a new calibration of the transducer in question.

  • Page 22: Probe Tone Speaker Calibration

    Service Manual AT235 4.1.2 Probe tone speaker calibration Select Probe Tone Speaker for calibration. Connect the probe to a 2 cc coupler with corresponding preamplifier and RMS-meter. Follow the on-screen instructions. NOTICE It is essential to click ‘Calculate Gain’ after each frequency level calibration...

  • Page 23: Transducer Calibration

    Service Manual AT235 4.1.3 Transducer calibration Select Transducer calibration to calibrate the transducers. Select the relevant transducer and follow the on-screen instructions. Upload defaults can be used when calibrating a new transducer in order to have a slide starting point closer to target.

  • Page 24: Volume Calibration

    Service Manual AT235 4.1.4 Volume calibration Select Volume Calibration. A CAT55 cavity set should be used. Background noise should be kept to a minimum. Follow the on-screen instructions. NOTICE Height above sea level must be set before the volume calibration is conducted.

  • Page 25: Pressure Calibration

    Service Manual AT235 4.1.5 Pressure calibration Select Pressure Calibration. Follow the on-screen instructions. The Safety Valve itself is NOT calibrated; this is only a verification of the sensor. The Safety Valve calibration lies in the hardware and is therefore verified in the production process.

  • Page 26: Calibration Standard For Audiometer

    Service Manual AT235 4.1.6 Calibration standard for Audiometer This chapter contains calibration standards for the Audiometer. Included here is an explanatory guide and a complete set-up of how to calibrate each transducer type. Tone standard is selected via AUD and ‘Standard’. The options are IEC or ANSI.

  • Page 27: Selecting A Transducer / How-To-Guide

    Service Manual AT235 Selecting a transducer / how-to-guide The following procedure is applicable for all transducer selections. Here, we have exemplified the procedure with the transducer type DD45, the standard transducer for this instrument. Please note that following this section, a list with the specific equipment requirements for each suitable transducer type can be found as well as photos of the correct equipment setup.
  • Page 28 Service Manual AT235 CALIBRATION OF DD45 Equipment needed for DD45 calibration Measuring amplifier • Acoustical IEC 60318-3 (IEC 303) coupler • • Frequency counter Correction values for coupler • From the AUD menu, select Transducer Calibration. Fig. 42 Place the transducer on the 6cc IEC 60318-3 (IEC 303) coupler Adjust the slider until the calibration level is obtained on the measurement amplifier (i.e.

  • Page 29: Transducer Types And Equipment Requirements For Calibration

    Service Manual AT235 4.2.1 Transducer types and equipment requirements for calibration Conduct the same procedure exemplified in Selecting a transducer / how-to-guide can be applied to all the transducers mentioned below. TDH39 Equipment needed for TDH39 calibration • Measuring amplifier Acoustical IEC 60318-3 (IEC 303) coupler •...
  • Page 30 Service Manual AT235 CIR 33 Equipment needed for calibrating the CIR 33 • Measuring amplifier • Acoustical IEC 60318-5 (IEC 126) coupler, fitted with eartip • Frequency counter Correction values for coupler • From the AUD menu, select Transducer Calibration.

  • Page 31: Testing The Tympanometer Functionality

    Service Manual AT235 Testing the Tympanometer Functionality This chapter explains how to test the tympanometer. Pressure test Test maximum pressure limit (red dotted line) Verify that the actual pressure does not cross the red dotted line at 600 daPa. While at the current pressure, watch the pressure value in the bottom of the pressure test view. Make sure that the pressure does not drop more than 5 daPa (0.5 daPa/sec) during the next 10 seconds.

  • Page 32: Diode Test

    Service Manual AT235 Diode test Select Diode. Operation of the multicolor probe status indication LED is now enabled for testing. This LED is situated at the rear of the probe body Each of the seven colors becomes selectable with the purpose of verifying properly functioning LED glows.

  • Page 33: Volume Test

    Service Manual AT235 Volume test Select Volume test. A dynamic readout of the different probe tones volumes is displayed. NOTICE At higher probe tone frequencies, larger volume capacities cannot be measured correctly Maximum volume for probe tone frequencies: Frequency Hz 1000 4.23...
  • Page 34 Service Manual AT235 Control whether the tone 226 Hz is audible in the probe tip. Place probe tip in a 2 cc cavity and check that the colored bar is changing color from blue to green. The volume shows 2 ml (1.90 to 2.10 ml).

  • Page 35: Attenuator Test

    Service Manual AT235 Attenuator test This test screen enables a manual check of all the input/output channels of the instrument. The screen is divided into three sections, and must be used with utmost caution, as very high sound intensities can be reached.
  • Page 36 Service Manual AT235 As illustrated below, make sure that the values are as follows: 0 dB = 3 V ± 0,3 V This particular example is measured on the left output. Fig. 53...
  • Page 37 Service Manual AT235 Now check at -60 dB = 3mV ± 0,3 mV This particular example is measured on the left output. Fig. 54 Repeat for the second attenuator using the Headset1Right output, making sure that the output corresponds with...

  • Page 38: Appendix A - Technical Specifications

    Appendix A – Technical Specifications General Medical CE-mark: The CE-mark in combination with MD symbol indicates that Interacoustics A/S meets the requirements of the Medical Device Regulation (EU) 2017/745. Approval of the quality system is made by TÜV – identification no. 0123.
  • Page 39 Service Manual AT235 NB noise – Ipsi, Reflex: 1000, 2000, 3000, 4000 Hz Stimulus duration: 750 ms Reflex acceptance: Adjustable between 2% and 6%, or 0.05 – 0.15 ml change of ear canal volume Intervals: Down to 1 dB step size.

  • Page 40: Calibration Properties

    Service Manual AT235 Calibration properties Calibrated transducers: Contralateral earphone: Telephonics TDH39/DD45 with a static force of 4.5 N 0.5 N and/or EARtone 3A and/or CIR insert phone Probe system: Ipsilateral Earphone: is integrated in the probe system Probe frequency transmitter and receiver and pressure...
  • Page 41 Service Manual AT235 The pressure accuracy is: ±10 daPa or 10%, whichever is greater. To minimize the influence of temperature, barometer pressure, humidity and height above sea level, it always recommended to calibrate the unit in the local positions. Temperature The temperature have no theoretic impact on the impedance calculation, but the temperature has influence on the electronic circuits.

  • Page 42: Reference Values For Stimulus Calibration

    Stimulus Correction Values 30,5 47.5 25.5 24.5 11.5 1000 1500 21 (1600 Hz) 2000 11.7 3000 -0.8 -0.5 31 (3150 Hz) 4000 -1.6 -0.8 32 6000 15.5 20.5 26 (6300 Hz) 8000 *All figures in bold are Interacoustics Standard values.

  • Page 43: Reference Equivalent Threshold Values For Transducers

    Service Manual AT235 Reference equivalent threshold values for transducers Impedance - frequencies and intensity ranges AT235 Maximums IMP TDH39 DD65v2 EARtone 3A / IP30 IPSI DD45 Center Reading Reading Reading Reading Reading Freq. Tone Tone Tone Tone Tone [Hz] [dB HL]...

  • Page 44: Survey Of Reference And Max. Hearing Level Tone Audiometer

    Service Manual AT235 Survey of reference and max. hearing level Tone Audiometer ANSI DD45 IEC DD45 Coupler: IEC 60318-3 1998 (6ccm) Coupler: IEC 60318-3 1998 (6ccm) Tone Audiometer Tone Audiometer Tone Narrow Band Noise Tone Narrow Band Noise PTB – DTU 2010 ISO 389-4 1994 PTB –...
  • Page 45 Service Manual AT235 ANSI CIR 33 IEC CIR 33 Coupler ANSI S3.7-1995 (HA-2) Coupler IEC 60318-5 2006 2ccm Tone Audiometer Tone Audiometer Tone Narrow Band Noise Tone Narrow Band Noise ANSI S3.6-2010 ANSI S3.6-2010 ISO 389-2 1994 ISO 389-4 1994...

  • Page 46: Survey Of Reference And Max. Hearing Level Tympanometer

    Service Manual AT235 Survey of reference and max. hearing level Tympanometer DD45 Contra TDH39 Contra Reading Reading Center Att. Center Att. Frequency setting Frequency setting Tone Tone [Hz] [dB HL [dB HL] [dB HL] [Hz] [dB HL [dB HL] [dB HL]...

  • Page 47: Appendix B - Block Diagram

    Service Manual AT235 Appendix B – Block Diagram...

  • Page 48: Appendix C - Parts & Accessories

    Service Manual AT235 Appendix C – Parts & Accessories ACCESSORIES PART NUMBER DESCRIPTION 8502562 Daily check cavity 8011296 CAT50 8108148 Diagnostic probe system 1077 8108189 Clinical probe system 1077 8503373 TDH39P contra headset P3045 neutral 8106919 DD45 contra headset P3045...
  • Page 49 Service Manual AT235 ACCESSORIES PART NUMBER DESCRIPTION 8517507 RadioEar Circumaural Headband cable 8517499 RadioEar Cushions for Circumaural Headbands 8105761 Strap -key kit 8104678 Assortment BET55 complete 8106038 Probe floss kit 8105696 Printer kit 1077 8106795 Wall mounting kit 1077 8103838...
  • Page 50 Service Manual AT235 CONSUMABLES PART NUMBER DESCRIPTION 8500580 Kit eartip adaptor, 6pcs 8500830 Eartip adaptor cleaning tool 8011348 Probe cleaning tool Eartips of various sizes (8511445) Types: umbrella, mushroom, flanged Single Use Eartip Box (8515491) TPR MPT-III thermal paper 8500610 Foam pad HBC39 headset.
  • Page 51 Probe tip kit 1077 incl. gasket 8004140 Cable for pump 24 pins 8000656 Pump module 8102693 Gasket 8527201 Mainboard with FW Replacement Kit AT235 1043 8108143 PCA keyboard 1077 8108144 Bottom 1077 8108145 PCA probe connection board 8106874 Rotary encoder 1077...
  • Page 52 Service Manual AT235 SPARE PARTS PART NUMBER DESCRIPTION 8102071 Display cable 1077 8004158 Cable for keyboard 40 pins 8101484 Rotary dial cover 1077 8108146 Top cabinet 8108147 Display 1077 8524210 Power supply 24V 60W UES65-240250SPA3 8507211 Contra headband P3045...

  • Page 53: Appendix D - Firmware Update Procedure

    AT235 Stand Alone Unit - Print Logo Update AT235 direct printout allows results to be printed directly after testing (via a supported USB printer – please contact Interacoustics customer service for a list of supported PC printers if in doubt). The printout logo can be configured via the audiometer itself (see below) or downloaded via the Diagnostic Suite (in the General Setup).
  • Page 54 Service Manual AT235 Ensure that FAT32 is selected as your file system - Leave other settings as listed. 10. Click start - depending on the size of your thumb drive this may take a moment. When the formatting is complete you will receive a pop-up indicating successful formatting.

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