AM232 Manual Audiometer Operating Instructions
Contents
1. 11 3 6 ROUTING Calibration CHECK isrsriscsransiariniiiiaris 12 3 7 Routine Test Administration cccccssseseeseeeerseeeeerees 12 Sead ES CHOI E 3 ecserin nieee nee e E 12 3 7 2 Range Extension Push Button F2 eee 12 3 7 3 Tone Type Selector F9 ccccceccccsseseessssseeeseeseaneeees 13 3 8 Typical Testing Session sisivecsic s0 dinissisisandiaasseteameavient 13 3 8 1 Pre est Review cccccccssssecesseeeersneeseesaeereetaneeeess 13 202 Famlianza lO esistere raia 13 3 8 3 Threshold Determination Pure Tone 14 3 8 4 Testing Procedure sss seessrrssessrrrrrssrrrrnenrrrrrrssrrrreee 14 Section 4 Routine Maintenance 4 1 Calibration i ccccecccsccsecceecseceeeeeceveceeeeeeeueeaueeaeenenss 15 A2 18 0 CONS seanieer a 15 4 3 Hum and Random Noise eeen 15 4 4 Distortion and Frequency Shift cccseseeesseeeerseeseees 15 4 5 Special Messages icciictssndieessenin sieve ocean ddeva diana ccessnteuneds 16 Bek CP inteareseeeeeentea tiie naar taneuenadoteeiiucacinsaiayiianinn 16 Ba cates ease etree eset tie ode eee tise 16 Service and Warranty Information Service and Repair ssessrrrssessrrrrresrrrrrrrnerrrrrrnssrrrrreesrrrrneene 17 BOC AINA OMA seipsecsieriensiiian ninin ane eiorinn tiaa 17 WY eee A 17 Rechargeable Battery Warranty cccccccssseeecseeeseeseeeeeeseees 17 Specifications iicrondsacpriaiin endaanivinarininciriiaanvannance 18 Bibliography eieireerpandiawaevctvennen saci cate u2. NOTE Descend in 10 dB steps and ascend in 5 dB steps b The threshold is considered to be the minimum dial setting at which a response has occurred two out of three times Record this setting on the audiogram form 3 8 4 Testing Procedure a Repeat 3 8 2 and 3 8 3 for each tone setting in the following order 1000 2000 3000 4000 6000 and 8000 Hz Retest 1000 followed by 500 and 250 If there is a difference of 20 dB or more between two successive octaves test the inter octave responses i e 750 1500 3000 Hz Record this information on the audiogram form b Repeat process 3 8 2 3 8 3 3 8 4 for the other ear Section 4 Routine Maintenance 4 1 CALIBRATION The biological listening check or routine check should be performed at least monthly see section 3 6 for description and explanation The following checks should be made at periodic intervals even if routine Calibration checks do not reveal any problems These procedures presup pose normal hearing on the part of the person doing the checking 4 2 EARPHONE CORDS With extended use earphone cords tend to fray internally at the junc tions of both earphone and audiometer connectors This fraying will ultimately either decrease the signal level in the associated earphone or Cause Signals to be intermittent as the cord is flexed To check for either condition set the audiometer frequency control F7 to 1000 or 2000 Hz set HL control F3 at a comfortable audib
3. claim adjuster Can inspect it as well As soon as the carrier has completed the inspec tion notify your Welch Allyn representative If the instrument must be returned to the factory repack it carefully in the original container if possible and return it prepaid to the factory for necessary adjustments Check that all accessories itemized in Table 1 1 are received in good condition If any accessories are missing contact your Welch Allyn rep resentative immediately See Specifications Section of this manual for the catalog numbers of accessories and also for a listing of optional accessories TABLE 1 1 Accessories Supplied Test Headset Assembly TDH39 Audiogram Pad 1 Pad of 50 Battery Pack Assembly used with model 23210 and 23215 only AC Power Cord rn 1 3 CONNECTORS CONTROLS AND INDICATORS FIGURE 1 1 Front and Rear Panel Front Panel Rear Panel BJ 1 3 1 The Front Panel Controls and Indicators Figure 1 1 F1 Power switch and indicator forON and OFF F2 Range extension push button allows operator to increase the Stimulus intensity 10 dB above the standard maximum HL at any frequency When in use a appears on the LCD F3 HL control for setting stimulus intensity level Level is indicated on LCD F4 Present bar for stimulus pres
4. other machines also reduces test validity be Cause it tends to mask the test signals particularly at the lower fre quencies where earphone cushions provide less effective attenuation An acoustically tested room may be required if ambient noise at the Subject s ears reaches an objectionable level i e sufficient to cause apparent hearing loss at the low frequencies Also Audiocups are avail able from Welch Allyn as an optional accessory If the test subject is in the same room as the audiometer it is recommended that the subject be seated about one meter 3 ft away from the instrument Maximum permissible test environment sound pressure levels are spe cified by American National Standard Criteria for Permissible Back ground Noise during Audiometric Testing 3 1 1991 Table 1 2 shows the maximum background levels that can be present inside the room while a valid hearing test is being conducted For more comprehensive information about hearing testing and hearing conservation refer to the Bibliography TABLE 1 2 Permissible Noise Levels Test Tone Frequency Hz 125 250 500 750 1000 1500 2000 3000 4000 6000 8000 Test Room Ears covered 34 0 22 5 19 5 21 5 26 5 26 5 28 0 33 5 34 5 38 0 43 5 maximum permissible octave band levels Ears covered 29 0 17 5 14 5 16 5 21 5 21 5 23 0 28 5 29 5 33 0 38 5 maximum permissible one third octave band levels Section 2 Battery Option 2 1 DESCRIPTION This section describes t
5. subject comfortably in the test area Explain the test procedure Assist subject with the earphones Select the desired tone type g Make appropriate entry on the subject s audiogram 3 8 2 Familiarization a Set the routing selector to route the test tone to the selected ear Demonstrate the 1000 Hz tone ata 40 dB level Duration of tone Should be between one and two seconds b Set HL control to 10 dB c Practice Beginning with the tone continuously on Present Bar held down gradually increase the intensity by turning the HL control until a response occurs Switch the tone off for at least two seconds and present the tone again at the same level If there is a second positive response proceed to threshold measurement If a second response does not occur repeat this step Practice is preliminary to threshold measurement determination and is to be completed at each new frequency setting mh Oman ogo 3 8 3 Threshold Determination Pure Tone a The level of the first presentation shall be 10 dB below the level at which the subject responded during the familiarization procedure Present the tone for a period of one or two seconds Time between tones can be varied but not shorter than the duration of the test tone itself After each failure to respond to a signal the level is in creased by 5 dB until the first response occurs After the response the intensity is decreased 10 dB and another ascending series IS begun
6. to prevent damage from mechanical shock 3 2 INSTRUCTING THE SUBJ ECT The operator should put the subject as much at ease as possible before the test begins In addition he she should try to make the Subject understand how the test is to be conducted and what the Subject will hear For the sake of uniformity an unvarying explanation IS advisable something close to the following I am going to place these earphones over your ears You will hear a variety of tones some high some low some loud some very soft Whenever you hear or think you hear one of those sounds raise your hand Lower your hand when you no longer hear the sound Remember that though some of the tones will be easy to hear others will be very faint Therefore you should listen very carefully and raise your hand whenever you think you hear the tone Modify the instructions accordingly if the optional response handswitch is to be used E 3 3 PLACEMENT OF EARPHONES The most important thing to remember is that a good Seal is required between the earphone cushion and the subject s head and ear To increase the likelihood of a good seal a Eliminate all obstruction between earphone and subject hair eyeglasses earrings hearing aids etc b Adjust the headband so that it rests solidly on the crown of the Subject s head and exerts firm pressure on both ears c Center earphones carefully over both ears earphone with red connector on r
7. 0 C Storage Powerline 40 F to 140 F 40 C to 60 C Storage Battery 40 F to 105 F 40 C to 40 C Humidity 5 to 90 Warm up Time 10 minutes for instruments stored at room temperature Mechanical Dimensions 13 25 W x 14 D x 3 75 H 33 66 cm x 35 56 cm x 9 53 cm Weight 5 6 lb 2 53 kg net 8 Ib 3 64 kg shipping 10 Ib 4 55 kg shipping with battery included Accessories Catalog Numbers Catalog Listings 23200 AM 232 Manual Audiometer AC Power USA 23205 AM 232 Manual Audiometer AC Power Export Specify country and voltage 23210 AM 232 Manual Audiometer AC Power and Battery USA 23215 AM 232 Manual Audiometer AC Power and Battery Export Specify country and voltage Supplied Accessories 23223 Test Headset TDH39 52300 Audiogram Forms 1 pad of 50 232001 Instruction Manual Optional Accessories 23220 Response Handswitch 23221 Patch Cord 2 Conductor 23222 Audiocups 72320 Replacement NiCad Battery Only 72329 Battery Pack Assembly Includes NiCad batteries May also be used with six 6 Size C Alkaline batteries not included Bibliography American National Standard Specifications for Audiometers ANSI S3 6 1989 Criteria for Permissible Ambient Noise During Audiometric Testing ANSI S3 1 1977 Methods for Manual Pure Tone Threshold Audiometry ANSI S3 21 1978 Michael P L and Bienvenue G R Noise Attenuation Characteristics of Supra Aural Audiometric Headset
8. 32 Manual Audiometer is operated until the battery charge has dropped below an acceptable voltage level the instrument will not function at all The display will be blank except for the LO BAT indica tion and the controls will not function To restore operation the bat teries must be recharged for some period of time up to 18 hours full charge or line power mains may be used If the audiometer is oper ated using line power mains with the rechargeable batteries in place some battery charging will occur 2 3 RECHARGE NiCad BATTERIES FIGURE 2 1 NiCad Battery Recharge Refer to Figure 2 1 when recharging NiCad batteries and proceed as follows a Be certain that the battery pack power cord is connected to the power cord receptacle on the back panel of the audiometer A b Connect the instrument power cord to the receptacle on the lower edge of the battery pack B c Plug the power cord into a wall outlet CAUTION Although no damage to the rechargeable NiCad batteries will occur if the pack Is left charging for more than the 18 hours required for a full charge the batteries should not be left charging for extended periods i e several days because the useful life of the rechargeable NiCad pack will be shortened Welch Allyn recommends unplugging the battery pack power input cord from the back of the audiometer and plugging the main line power cord
9. WelchAllyn AM 232 Manual Audiometer Operating Instruction Manual Contents Section 1 Introduction 1 1 Descriptio especseeecnceccteccretac tie yeoatasaeconatseseaseetsnaecesaeseiens 1 1 2 Unpacking and INSP SCHON ociera 1 1 3 Connectors Controls and Indicators eeen 2 1 3 1 The Front Panel Controls and Indicators Fig 1 1 3 1 3 2 Rear Panel Connectors and Indicators Fig 1 1 3 De MDO cess anorettteriesvocaetaet A E EE 3 Ea APS AON eA AEA 4 1 5 Pre Test Procedure esssssssssssesssssrrrrrrrrersssrrrrrrrrrresrrrnn 4 1 5 1 Pre Test Noise Recover Period nennen 5 1 5 2 Elimination of Ambient NOISC c ccsseeeecsseseereeeeeers 5 Section 2 Battery Option 2L DESCDUON catesict secs cetatasdetesaseaesdtenedeaneeatdvalentetcoutinan 6 2 2 NiCad Battery Operation ccccccseseeeseessesseseeeeeeeeeees 6 2 3 Recharge NiCad Batteries cccccccecssessesseeeeeeeeeeeees 7 2 4 To Replace NiCad Batteries ccececccssssseseeeeeneeeees 8 2 5 Alkaline Battery Installation Operation ccccceeeeeeseees 9 Section 3 Operation Dok Preliminary OOK saree ee ctyaecececnsethotsntaciaewiieesenerieeaceon 10 32 MAS HUCUING Me UDI CE teu iescucennoseadaceneoeatiace moe aeadeannees 10 3 3 Placement of Earphones scsiascivcesivsrsinarseversivercinorsinancees 11 3 4 Response Handswitch ccssscccssssseesssssssessesessersaeass 11 35 A diogram FON siissiiiriirissisisriissiiiasiiisniironiisiiniii
10. e by returning the instrument registration card or by contacting Welch Allyn s Technical Service De partment as listed above A moderate fee is charged for recalibration WARRANTY NOTE Return of the instrument registration card is required for proof of purchase and warranty validation Welch Allyn Inc warrants the AM 232 Manual Audiometer to be free of original defects in material and workmanship and to perform in accordance with manu facturer s specifications for a period of one year from the date of purchase If this instrument or any component thereof is found to be defective or at vari ance from the manufacturer s specifications during the warranty period Welch Allyn will repair replace or recalibrate the instrument or component s at no cost to the purchaser This warranty only applies to instruments purchased new from Welch Allyn or its authorized distributors or representatives The purchaser must return the in strument directly to Welch Allyn or an authorized distributor or representative and bear the costs of shipping This warranty does not cover breakage or failure due to tampering misuse neglect accidents modification or shipping and is void if the instrument is not used in accordance with manufacturer s recommendations or if repaired or serviced by other than Welch Allyn or a Welch Allyn authorized representative No other express or implied warranty Is given RECHARGEABLE BATTERY WARRANTY Welch Allyn nicke
11. enced in IEC 601 Standard a lt 2 1 4 INSTALLATION Warning The AM 232 Manual Audiometer is designed to be used with a hospital grade outlet Injury to personnel or damage to equipment can result when a three prong or two prong adapter is connected between the AM 232 Manual Audio meter power plug and an AC outlet or extension cord Additionally the AM 232 M anual Audiometer is equipped with a specific power transformer which should not be interchanged with any other transformer or supply bA The above symbol indicates the location of a service adjustment part and is intended for service personnel use only The AM 232 Manual Audiometer is a specifically calibrated audiometer and the periodic service and adjustments which the instrument may require should be done only by an authorized Welch Allyn service technician Plug the power module into the appropriate jack R1 on the back panel of the instrument then plug the other end into a line power mains outlet Plug the earphones into the earphone jacks R3 on the rear panel Note the symbol along the top of the front panel which indicates which is right and which is left The right earphone Is red the left earphone is blue Turn the power switch to ON NOTE For battery operation please refer to Section 2 15 PRE TEST PROCEDURE NOTE The AM 232 Manual Audiometer is a versatile audiometer designed for use in doctors offices schools industria
12. entation F5 Stimulus being presented via earphone Presentation indicated by illuminated green LED F6 Subject response indicator shows the operator when the test Subject has pressed the handswitch button by an illuminated green LED with optional handswitch only F7 Control for setting stimulus frequency Frequency is indicated in window adjacent to control F8 Routing switch for stimulus presentation to the earphone Left or right indicated by illustration of subject F9 Switch for setting the stimulus tone type FM warble tone EE steady tone BEEE pulsed tone F10 Low battery indicator to alert the operator of a limited oper ating time Recharge or replace batteries dependent on whether NiCad or Alkaline batteries are used 1 3 2 Rear Panel Connectors and Indicators Figure 1 1 R1 Power input jack 5 pin DIN Connector with front panel illus tration showing Its location and a rear panel label giving the input power specifications R2 Earphone output jacks standard phone jacks Front panel illustration shows left and right phone R3 Response handswitch input jack standard phone jack with front panel illustration showing location 1 3 3 Symbols A Attention consult accompanying document for instructions or warnings pertaining to these parts R Entry by qualified service personnel only This symbol is located inside the storage compartment It denotes a Type B Class Il product per IEC 878 as refer
13. he battery option of the AM 232 Manual Audio meter It pertains only to those customers who purchased Models 23210 or 23215 with the battery pack installed or to those who later purchased the 72329 Battery Pack Assembly In both cases a re chargeable NiCad battery is included 2 2 NiCad BATTERY OPERATION The AM 232 Manual Audiometer battery option is supplied with an in Stalled rechargeable NiCad battery pack It requires about 18 hours to fully charge and will provide about 22 hours of continuous operation when fully charged The green LED on the pack itself will be lit when charge is getting low so the operator will know when to recharge the batteries When LO BAT appears the instrument will operate continu ously for about two more hours before it shuts down completely NOTE In no instance will loss of battery power affect instrument calibration To save battery life the AM 232 Manual Audiometer has a special sleep mode in which the audiometer will shut down after five minutes of no operation The operator will know the instrument is asleep be cause the LCD will show three dash lines To wake up the instru ment the operator only needs to press the present bar There is no danger of presenting a loud tone to the test subject when the instru ment wakes up because no tone is presented until the audiometer is awake In addition the instrument automatically resets its output to 0 dB HL If the AM 2
14. his control allows the operator to present tones of up to 10 dB above the standard maximum HL at any frequency It will only function when the intensity is set within 10 dB below the maximum standard intensity at any frequency This feature requires an extra step to access or use the highest available intensities requiring the operator to make note of those individuals requiring testing at these levels It also prevents acci dental presentation of the highest intensities to normal subjects and it alerts the operator to present the stimulus for only brief periods of time 2 ee To enable the range extension feature simply push the button labeled 10 dB Note the appearance of the sign on the LCD To disable the feature either push the button a second time reduce the intensity with the HL control knob to 20 dB below the standard maximum HL or change any other parameter frequency knob routing switch 3 7 3 Tone Type Selector F9 This control allows the operator to choose the type of tone presented to the test subject It can be set on steady pulsed 2 5 pulses per second or FM warble tone Pulsed tones and warble tones are often used with difficult to test subjects such as children and hard of hearing individuals because they hold the subject s attention better than the steady tone 3 8 TYPICAL TESTING SESSION 3 8 1 Pre Test Review a Turn the instrument on Check that the earphones are operating properly Seat
15. ight ear Take care to eliminate any visible gaps between earphone cushions and portions of the subject s head and the ear on which the cushion rests 3 4 RESPONSE HANDSWITCH If the optional Response Handswitch is to be used insure that the plugs and jacks are properly connected The subject response indica tor on the front panel will be illuminated when the subject presses the response button 3 5 AUDIOGRAM FORM The AM 232 Audiogram Form See Figure 3 1 consists of three distinct parts e Space for entering information about the person to be tested e A convenient chart for manually plotting test data e Space for entering comments about the subject or the test AM 232 AUDIOGRAM Age Sex Audiometer Model No Job Description Serial No Examiner Signature SYMBOLS COMMENTS HEARING LEVEL IN DECIBELS ISO 389 1985 ANSI S3 6 1989 WelchAllyn 3 00 80 Printed in U S A Customer Reorder No 52300 TONE FREQUENCY Hz 232002 FIGURE 3 1 Audiogram Form RR 3 6 ROUTINE CALIBRATION CHECK The microprocessor controlled circuitry and quality construction of the AM 232 Manual Audiometer will provide long and reliable service It is good practice however to make and file at the start of each month s testing the audiogram of a single subject or of a small group of subjects who are likely to be routinely available for this purpose Where physical arrangeme
16. into the jack if main line power is to be used most of the time A 2 4 TO REPLACE NiCad BATTERIES Please refer to Figures 2 2 2 3 2 4 and proceed as follows a Unplug the AM 232 Manual Audiometer from the line power mains b Remove the two screws on the battery pack cover and lift off the cover c Pull the NiCad battery out of the pack The battery Is actually a set of six batteries wrapped in plastic but they will be removed as a Single unit FIGURE 2 2 FIGURE 2 3 FIGURE 2 4 Battery Cover NiCad Battery Pack Internal View of Removal Removal Battery Compartment d Carefully disconnect the lead wires of the NiCad battery from the battery compartment by removing the small connector Remove NiCad pack e Attach the lead wire connector on the new NiCad battery to the mating connector within the battery pack base Place the new NiCad into the battery pack f Replace the battery pack cover There is only one way that the cover can be replaced and the screws tightened Note that the screw housing is longer on one end Orient the top cover so that it will sit flat on the top of the battery compartments and replace screws BE 2 5 ALKALINE BATTERY INSTALLATION OPERATION For longer continuous battery operation such as periods when recharg ing on a regular basis is not possible the rechargeable batteries can be replaced with six size C alkaline batteries These batteries will provide about 45 hou
17. l cadmium batteries are guaranteed by Welch Allyn for two years from date of manufacture when used in Welch Allyn instruments only Defective batteries will be replaced on a pro rata basis should failure occur prior to expiration date on battery Re Specifications Standards The AM 232 meets ANSI S3 6 and IEC 645 Type 4 Audiometer Standards and IEC 601 1 CSA C22 2 No 601 1 and UL 544 electrical standards Frequency Range Discrete Frequencies 125 250 500 750 1000 1500 2000 3000 4000 6000 8000 Hz Accuracy 3 Total Harmonic Distortion lt 2 Intensity Ranges 125 Hz 10 to 50 dB HL 500 to 6000 Hz 10 to 90 dB HL 250 and 8000 Hz 10 to 70 dB HL increments of 5 dB steps NOTE A 10 dB switch extends maximum at all frequencies by 10 dB Accuracy 125 to 4000 Hz 3 dB 6000 to 8000 Hz 5 dB Signal to Noise Ratio gt 70 dB Tone Type Rise Fall Time 20 to 50 msec Continuous Steady when present bar depressed Pulse 2 5 pulse Sec FM 5 Hz 5 Headset Telephonics TDH39 Earphones with MX41AR Cushions 60 ohm impedance Power Line Voltage 100 to 120 V or 200 to 250 V 410 Range 50 to 60 Hz 45 Consumption 9 Watts Battery Types Rechargeable NiCad or Non Rechargeable Alkaline Range 7 0 V to 9 0 V Capacity NiCad 22 hours continuous operations Alkaline 45 hours continuous operations EA Environmental Temperature Operating 60 F to 105 F 15 C to 4
18. l settings the military etc This manual therefore employs the generic term subject to identify the person whose hearing is being evaluated Although the AM 232 Manual Audiometer is simple enough to be oper ated by practically anyone any program aimed at obtaining reliable re cords of hearing thresholds should be staffed and supervised by appro priately trained individuals Training courses leading to certification are available for audiometric technicians in most urban areas Two prerequisites are of particular importance to the procurement of reliable audiograms e Prior to testing allow adequate time for the subject to recover from the effects of previous exposure to high level sound e Tests should be done in a quiet area EA re 1 5 1 Pre Test Noise Recover Period Exposure to high levels of sound unmuffled lawn mowers many power tools loud music gunfire tends to create a temporary threshold shift TTS which diminishes with time after exposure Any subject tested soon after such exposure may manifest a hearing loss that does not re flect his or her normal hearing threshold It is therefore important that the testing procedure prescribe some time interval usually at least 16 hours between the last exposure to high level sound and the adminis tration of any hearing test 1 5 2 Elimination of Ambient Noise Excessive noise in the test environment such as that produced by con versation typewriters or
19. le level press the Present Bar F4 and flex earphone cord next to plug at both ends listening for intermittent signal abrupt changes in signal level or a scratchy sound superimposed over the signal that coincides with the flexing of the cord The presence of any of these three conditions signifies that the cord should be replaced Repeat the test for the other earphone 4 3 HUM AND RANDOM NOISE This test can be made during the check for attenuator noise With the instrument set on 1000 Hz move the HL control F3 from 0 to 60 dB and listen for low frequency hum 60 to 120 Hz and random noise hiss or low rushing sound at all attenuator levels Some audible random noise at levels above 60 dB is permissible Below 60 dB however only the Signal should be audible Any of these noises can be confused with the Signal by naive subjects and affect the accuracy of the audiogram Sched ule the audiometer for immediate service if any of the three is detected 4 4 DISTORTION AND FREQUENCY SHIFT This check can be best made by listening to the output of the AM 232 Manual Audiometer through the earphones while presenting all 11 fre quencies at a loud but not uncomfortable level 70 to 80 dB HL for normal ears Listen for rattling rasping or distortion in the tones presented Listen also to ascertain that signal frequencies change plausibly when the frequency selector F7 is moved to a new position If distortion is heard in one earphone b
20. nts permit the operator can serve as a Subject This procedure should commence when the audiometer is installed and be performed each month thereafter If the AM 232 Manual Audio meter is to be used to monitor employee thresholds as part of an indus trial Hearing Conservation Program this biological listening check must be done at the beginning of each day the audiometer Is to be used per CFR 1910 95 Occupational Noise Exposure March 8 1983 Since individual thresholds can shift up or down as much as 5 dB from one day to the next variation within this range may be considered ac ceptable Variations that exceed this range however are likely to reveal problems that require attention The routine maintenance checks de scribed in Section 4 may suggest the source and solution to the prob lem If they do not the instrument should receive technical service by a certified technician before further use 3 7 ROUTINE TEST ADMINISTRATION 3 7 1 HL Control F3 The HL control will increase or decrease the presented intensity in 5 dB HL steps with the currently available intensity appearing on the LCD Rotating the control knob clockwise increases the intensity Ro tating the control knob counter clockwise decreases intensity When the maximum or minimum available intensity is reached for any fre quency the display will flash to alert the operator he she cannot ex ceed the available range 3 7 2 Range Extension Push Button F2 T
21. rs of continuous operation The low voltage indicator works the same way for the alkaline batteries as it does for the NiCad batteries The words LO BAT will appear on the LCD when about six hours of continuous battery operation remain In addition the sleep mode also works with the alkaline batteries to prolong their useful life To install the alkaline batteries refer to Figures 2 2 2 3 2 4 and proceed as follows a Unplug the AM 232 Manual Audiometer from the line power mains b Remove the two screws on the battery pack cover and lift off the cover c Pull the NiCad battery out of the pack The battery Is actually a set of six batteries wrapped in plastic but they will be removed as a Single unit d Carefully disconnect the lead wires of the NiCad battery from the battery compartment by removing the small connector Remove NiCad pack e There are six spring mounts on the top and bottom of the battery compartment to hold the alkaline batteries The label on the bot tom surface of the compartment indicates the correct position for each battery Place each one of the six batteries into the pack matching the polarity or as shown on the label f Replace the battery pack cover Make certain that the cover is po Sitioned with the spring mounts touching the batteries There is only one way that the cover can be replaced and the screws tight ened Note that the screw housing Is longer on one end Orient the top
22. s Using the Models MX41 AR and 51 Earphone Cushions J Acoust Soc Am 70 5 Nov 1981 1235 1238 Newby H A Audiology 4th ed New J ersey Prentice Hall Inc 1979 U S Department of Labor Occupational Noise Exposure CFR 1910 95 March 8 1983 WelchAllyn Welch Allyn Inc 4341 State Street Road P O Box 220 Skaneateles Falls N Y 13153 0220 U S A Tel 800 535 6663 in U S A only or 315 685 4560 Fax 315 685 3361 Printed in U S A 1717 0101 Rev 3
23. so that it will sit flat on top of the battery compartment and replace screws NOTE If the alkaline batteries are not going to be used on a regular basis they Should NOT be stored in the audiometer They should be removed from the battery pack and stored in a cool dry place Section 3 Operation Throughout this section there are references to front panel F and rear panel R connectors controls and indicators Please refer to Section 1 3 and Figure 1 1 for specific descriptions and locations 3 1 PRELIMINARY CHECK Prior to testing ensure that the power cord and earphone cords are plugged in R1 and R2 respectively Turn the audiometer on select the desired tone type F9 pulsed steady or FM and make whatever nota tions your procedure requires on the audiogram form CAUTION Always handle earphones with care Neither drop them nor permit them to be Squeezed together Severe mechanical shock may change their operating characteristics and require their replacement IMPORTANT Always clean and maintain your earphone cushions for hygiene purposes Check periodically for cracking or signs of wear Cleanse cushions daily or after each use depending upon population being tested Use a solution of diluted alcohol or mild soap and water taking care not to get any of the cleaning solution into the earphone speaker Use earphones only when completely dry Insert the earphone cords between the earphone cushions during storage
24. ureenvnirennne 20 Section 1 Introduction 1 1 DESCRIPTION The Welch Allyn AM 232 Manual Audiometer is a single channel pure tone air conduction portable instrument designed to provide basic audiometric capability for physicians offices schools and industry The lightweight design allows easy transport to a variety of testing locations and the built in storage cavity and case provide enough room to contain all instrument accessories The clearly labeled front panel controls and full frequency range make accurate reliable testing a simple matter for any user The Welch Allyn AM 232 Manual Audiometer Is a precisely designed and calibrated instrument With proper care it will deliver accurate sound pressure levels for years to come The Welch Allyn AM 232 Manual Audiometer should be recalibrated yearly or sooner if a prob lem develops See Section 4 1 2 UNPACKING AND INSPECTION Although your Welch Allyn AM 232 Manual Audiometer was carefully tested inspected and packed for shipping it is good practice after re ceiving the instrument to immediately examine the outside of the con tainer for any signs of damage Notify your distributor if any damage Is noted Carefully remove your Welch Allyn AM 232 Manual Audiometer from its shipping container If the instrument appears to have suffered mechani cal damage notify the carrier immediately so that a proper claim can be made Be certain to save all packing materials so that the
25. ut not in the other the chances are high that the earphones are at fault and should be replaced In any case the audiometer should be scheduled for immediate maintenance 2 4 5 SPECIAL MESSAGES The AM 232 Manual Audiometer is a microprocessor controlled instru ment which performs a self check each time the instrument is turned on the self check does not occur when instrument operation resumes from sleep mode Certain messages will be displayed to the operator on the front panel LCD if any error in the instrument operation is de tected These messages are described below 4 5 1 CAL When a transducer or frequency is selected which has a calibration error e g right earphone at 2000 Hz the word CAL will be display ed to the operator The audiometer will not function at this frequency with this transducer so that no invalid results can be recorded The word CAL will be displayed as long as the problem transducer and fre quency are selected If the calibration error is an isolated situation changing either the frequency or the transducer e g left earphone at 3000 Hz will restore normal instrument function As in the case with any instrument malfunction a certified service tech nician should be contacted immediately Remember to make note of the combination of transducer and frequency which resulted in the CAL message 4 5 2 Exx When an error code consisting of an E and a two digit number
26. xx number appears on the audiometer s display a system error has been detected The AM 232 Manual Audiometer will enter a lock out mode which will not permit the instrument to operate The specific error code will remain on the display for several seconds then the instrument will shut itself down completely Should an Exx appear on the LCD take the following steps a Power down power up again This could be only a temporary failure and may never appear again However should the Exx message appear again proceed to steps b and c b Write down the numbers that appear on the display c Contact your certified service representative and give them the Specific numbers you have recorded Service and Warranty Information SERVICE AND REPAIR Repair must be performed by authorized personnel Failure to do so invalidates the AM 232 Manual Audiometer warranty For customers in the United States or Canada please contact Welch Allyn for information on where to return your AM 232 Manual Audio meter for service Technical Service Department Technical Service Department Welch Allyn Inc Welch Allyn Canada Limited 4341 State Street Road 160 Matheson Boulevard East Skaneateles Falls NY 13153 0220 Mississauga Ontario Canada L4Z 1V4 Tel 1 800 535 6663 Tel 1 800 561 8797 In U S A only in Canada only RECALIBRATION Welch Allyn recommends that the AM 232 Manual Audiometer be recal lorated annually Arrangements may be mad
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