Huntingdon Fusion Techniques HFT®’s PurgEye® 100

09 August 2018

Inert shielding gas is used to protect high integrity welds from oxygen and water vapour during the TIG (GTAW) and Plasma (PAW) welding processes.

When welding tanks, vessels, chambers and pipes, the most cost effective inert gas used for shielding is argon. As argon is heavier than air, it displaces the air containing oxygen and water upwards and out of a vent tube which can be fed to a Weld Purge Monitor®.
This process, called Weld Purging, will ensure oxide free, metallurgically sound welds in critical joints made of stainless steel, titanium and other refractory metals. 

During stainless steel welding, the oxygen content must be purged down to a level lower than 100 ppm. Titanium and other sensitive materials may have to be purged down to 20 parts per million to obtain oxide free joints. Measuring the oxygen level in shielding gas is therefore crucial. 

The low cost, hand held, battery operated PurgEye® 100, designed and developed by Huntingdon Fusion Techniques HFT® is perfect for obtaining zero colour, oxide free welds in stainless steel, reading accurately from atmospheric oxygen level (20.94%), right down to 100 ppm (0.01%). 
The PurgEye® 100 is IP65 rated and comes with leak-tight push buttons, auto calibration features, vacuum-sealed leak-tight probe assembly, wrist/neck strap and tripod mount long life sensor.

The extra long life sensor provides approximately 18 months life before it requires changing. A low sensor indicator will appear on the screen, warning that a new sensor is required. Once that icon appears, it provides the user with adequate time to obtain a new sensor, which can be fitted like changing a battery and the monitor can be re-calibrated easily by the user. 

It is important not to use low cost oxygen analyzers or other oxygen safety monitors as they are calibrated for accuracy at ambient conditions and therefore not suitable for measuring purge levels at 0.01% as the PurgEye® 100 does.

Image courtesy of Huntingdon Fusion Techniques HFT®