Wehnelt Removal Tool

Wehnelt Removal Tool

This tool is used for the part of replacement process of the Wehnelt (electrode) for the electron gun in the scanning electron microscope when the filament reaches its lifetime.
With the conventional tool, it takes many hours to remove the Wehnelt, and also very carefulness is required for the replacement because the temperature of the Wehnelt is very high immediately after the filament wire is broken.
The use of this new tool enables the Wehnelt electrode to be easily removed, and shortens the replacement time with a facilitated cooling of the Wehnelt.


Wehnelt Removal Tool

Simple tool operation

Single-touch operation to raise, lower, and rotate the fastening ring, allows for the holding and removal of the Wehnelt.

Raise fastening ring and rotate left → fasten arm.
Lower fastening ring and rotate right → release arm.
Wehnelt can be safely and easily held and removed.
Wehnelt is being held.

Wehnelt can be safely and easily held and removed.

In the previous procedures, the Wehnelt was covered with the conventional tool and then, it was fastened with screws. But as an improvement, the use of this tool enables you to easily catch the Wehnelt by inserting three arms into the removal hole.
Since the temperature of the Wehnelt is very high immediately after the filament wire is broken, this tool is designed so that you can catch the Wehnelt at the place as far as possible.
Wehnelt is being released.
Wehnelt is being released.

Simplified cooling of the high-temperature Wehnelt to shorten the replacement time

The Wehnelt held by this tool is exposed. So, you can dip the tool into a solvent for cooling it while holding this Wehnelt.
In the previous procedures, you have to wait until the Wehnelt cools down to a state where you can replace it, so it is inconvenient. The use of this new toll shortens the replacement time.
sem series

Commonly used for many JEOL general-purpose SEMs

The common Wehnelt and filament are used for JEOL compact SEMs, which include JSM-T series, JSM-5000 series and currently-supplying SEMs.

Method for Use

Please see an attached video file.

◆Click the "replay" button in the box above, and the movie will start (for 40 seconds)◆

Size and Weight of Tool

Tool size

Basic unit:120 mm × 45 mm dia.
Fastening ring:60 mm dia. × 20 mm × 7 mm (thick)

Tool weight


Applicable Instruments (Models)

JSM-IT100 / IT300 / IT500 series
JSM-6010 / 6510 / 6390 / 6380 / 6360 / 6060 series
JSM-6610 / 6490 /6480 / 6460 / 5900 / 5800 series
JSM-5600 / 5500 / 5400 / 5300 / 5200 series
JCM-5100 / 5700,JSM-T series


P/N Product name Number


Wehnelt removal tool