2PRELIMINARY EXAMINATION ................................................................................................ 3GENERAL DESCRIPTION......................................................................................................... 4ABBREVIATIONS................................................................................................................... 4SPECIFICATIONS .................................................................................................................. 5PRECISION AND ACCURACY ................................................................................................... 5PRINCIPLE OF OPERATION .................................................................................................... 6FUNCTIONAL DESCRIPTION ................................................................................................... 7GUIDE TO DISPLAY CODES .................................................................................................... 9GENERAL TIPS FOR AN ACCURATE MEASUREMENT .................................................................11MEASUREMENT PROCEDURE ................................................................................................13VALIDATION PROCEDURE .....................................................................................................15CALIBRATION PROCEDURE ...................................................................................................16BATTERY REPLACEMENT .......................................................................................................18ACCESSORIES .....................................................................................................................18DECLARATION OF CONFORMITY .....................................................................................19WARRANTY .........................................................................................................................19Dear Customer,Thank you for choosing a Hanna product. This manual will provide you with the necessary informationfor the correct use of the instrument. Please read it carefully before using the meter. If you needadditional technical information, do not hesitate to e-mail us at tech@hannainst.com.This instrument is in compliance with directives.All rights are reserved. Reproduction in whole or in part is prohibited without the written consentof the copyright owner, Hanna Instruments Inc., Woonsocket, Rhode Island, 02895 , USA.TABLE OF CONTENTS19Recommendations for UsersBefore using these products, make surethat they are entirely suitable for yourspecific application and for theenvironment in which they are used.Operation of these instruments may causeunacceptable interferences to otherelectronic equipments, this requiring theoperator to take all necessary steps tocorrect interferences.Any variation introduced by the user tothe supplied equipment may degrade theinstruments' EMC performance.To avoid damages or burns, do not putthe instrument in microwave oven. Foryours and the instrument safety do notuse or store the instrument in hazardousenvironments.HI 95721 is warranted for two years against defects in workmanship and materials when used for itsintended purpose and maintained according to the instructions.This warranty is limited to repair or replacement free of charge.Damages due to accident, misuse, tampering or lack of prescribed maintenance are not covered.If service is required, contact your dealer. If under warranty, report the model number, date ofpurchase, serial number and the nature of the failure. If the repair is not covered by the warranty, youwill be notified of the charges incurred.If the instrument is to be returned to Hanna Instruments, first obtain a Returned Goods AuthorizationNumber from the Customer Service Department and then send it with shipment costs prepaid. Whenshipping any instrument, make sure it is properly packaged for complete protection.To validate your warranty, fill out and return the enclosed warranty card within 14 days from the dateof purchase.WARRANTYDECLARATION OF CONFORMITYWARRANTYHANNA instruments® reserves the right to modify the design, construction and appearance of itsproducts without advance notice.