User Guides < Download PLEASE READ : All reasonable care has been taken in the production of the User Guides provided in our website. If you find any points which are unclear or in error, please contact your local distributor or the HIOKI International Sales & Marketing Department at os-com@hioki.co.jp. In the interest of product development, the contents of the following user guides may be subject to revision without notice.  Recording Equipment  Environmental Measuring Instruments WAVE COMPARATORS 8730/31-10 User Guide on how to effectively utilize the many convenient features of the innovative instrument (4.2MB) MEMORY HiLOGGER 8420-01 and 8421-01 User Guide concerning Noise Countermeasures (218KB)  Safety Standards Measuring Instruments  Electronic Measuring Instruments User Guide on Safety Standards, testing methods and test instruments for medical electrical equipment (1.3MB) BATTERY HiTESTERs 3550 Series User Guide (496KB) m-ohm HiTESTER 3540 User Guide Applied Ways of Usage (730KB)  Power Measuring Instruments  Field Measuring Instruments Guidebook for Power Quality Measurement (PW3198, 3197/3196) Helpful Hints for Measurement and Case Studies (3.46 MB) (2011-09-01 updated) CLAMP ON POWER HiTESTER 3166 User Guide How to Calculate the FD Storage Capacity and Open FD Data with Excel (226KB) 3129 Phase Detector Series User Guide Why Non-Metallic Voltage Phase Detection is the ONLY safe way to detect for phase rotation (3.4 MB)