WT500 Mid-Range Power Analyzer


This firmware is intended to upgrade the WT500 to the latest version.


Please read installation procedures throughout before performing the installation.
Each zip file contains firmware program file and an installation procedure.

Revision History

Version Release Date Content
1.31 Jan 31,2020
  • Support additional suffix code for power cords corresponding to Taiwanese RoHS.
1.21 Sep 9,2016
  • Support for WTViewerEfree software.
  • Improve response of [*TST?] command.
  • Improve freeze phenomena during long period continuous measurement.
1.12 Sep 17,2014
  • Support for options (/US, /P14 and /P17).
1.11 Feb 5,2013
  • Support USB driver parts change.
1.03 May 25,2010
  • Fixed polarity of phase angle calculation of three phase input.
1.02 Dec 19,2008
  • New Functions: add large font character.
1.01 Jun 30,2008
  • First delivery version.



Please read Software Agreement carefully before downloading.


Version 1.31
Release Date Jan 31,2020
File Name (for USB memory)
4.6 MB


Type Firmware* Registration is required to download.


* Software Agreement
  • The property rights, proprietary rights, intellectual property rights, and all other rights associated with the software are held by Yokogawa Electric Corporation.
  • Under no circumstances is any dumping, reverse compiling, reverse assembly, reverse engineering, or any other kind of alteration or revision of this software allowed.
  • This software is offered free of charge, but no unlimited warranties are made against any defects whatsoever.
  • Also, Yokogawa may not be able to accept inquiries regarding repair of defects in or questions about this software.
  • The contents of this software are subject to change without prior notice as a result of continuing improvements to the software\'s performance and functions.
  • Yokogawa bears no liability for any problems that may occur during download or installation of this software.
  • Use of the Yokogawa Web site is at the user\'s own risk.
  • Any parties contributing to the creation or distribution of the contents on the Yokogawa Web site shall bear no responsibility whatsoever for any damages occurring as a result of the use of said contents.

Downloading of the software indicates acceptance of the software agreement.

Related Products & Solutions

WT500 - Mid Range

  • Power and Harmonic (THD) Measurements with Independent Range Controls
  • Efficiency measurements of AC/DC or DC/AC Inverters & Motors