The Plasma analyzes nitrogen in argon or helium, all in one device

Specifically designed for air separation unit (ASU) plant operations, the Plasma delivers an accurate, highly stable and reliable measurement, with high sensitivity with standard ranges between 100ppm and as low as 1ppm.

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Your analyzer will be assembled in one of our state-of-the-art engineering centers and rapidly dispatched to your site

SERVOPRO Servomex Plasma

Get unmatched stability

Chris Davis
Product Manager

Using high-specification, patented Plasma Emissions Detector (PED) sensing technology that features an intelligent micro-processor platform for unsurpassed stability and selectivity, the Plasma provides continuous monitoring of N2 in pure Ar and/or He.

The Plasma combines high stability performance and flexibility, delivering an analytical solution that meets the needs of process control and quality checking in cryogenic air separation and gas bottling applications.


An adaptable, zero-maintenance solution

The Plasma delivers an adaptable solution that meets precise application requirements, with a choice of three measurement ranges in both a standard or high purity setting mode, and an automatic range change facility for optimal output resolution.

In addition, the Plasma requires zero maintenance and enhanced device interaction, and RS232 ACSII (optional). This results in an analytical solution capable of delivering on all levels.

Performance and accuracy you can rely on

When you work in cryogenic air separation or gas bottling plants, producing Ar, you need an analyzer that offers the most reliable and accurate continuous monitoring of N2 or trace impurities. The freedom to configure a suitable device easily and select one that meets your specific needs is also essential; including the flexibility to detect either Ar or He or both gas streams simultaneously. No matter your application needs, you’ll also want a device that reduces ongoing costs and deliver comprehensive remote interaction through a choice of communications platforms. And we don’t believe you should have to compromise.

A no-compromise solution

The Plasma is the most stable continuous N2 in Ar and trace N2 impurity measurement analyzer available. With easy set-up that includes configuration of three range options, this analyzer adapts to your specific application needs. The Plasma also enhances safety and reduces downtime potential through its fault alarm and contact alarm features.

Service team checklist

Maintenance-free affordability

The Plasma provides impressive affordability to match its accuracy and measurement stability, with no ongoing maintenance requirements. The ability to remotely interact with this analyzer using a network connection delivers additional value by allowing offsite troubleshooting and parameter checking. This dramatically reduces lifetime cost-of-ownership, so you can leverage considerable savings over comparable devices.

Man with Servomex System components

Building a gas analysis system? We can help

If you want to integrate the Plasma into a new or existing system, our expert team can ensure optimum results. Contact our experience systems engineers for the best advice.

Discover the benefits of Plasma sensing

The Plasma delivers sensitive and reliable PED monitoring of nitrogen in cryogenic air separation and gas bottling plants.

Wide measurement range

Nitrogen concentration readings in the 0-1ppm, 0-10ppm and 0-100pmm ranges are available from the Plasma, with higher ranges on request.

Flow control for stability

An electronic flow control system ensures the Plasma has low flow consumption and optimized reading stability.

Electrical safety compliance

The Plasma meets safety standard IEC 61010-1: Ed 3, and complies with Low Voltage, EMC and applicable Directives.

Unrivalled performance

  • PED sensor technology uses an intelligent micro-processor for unrivalled reliability/gas specific selectivity
  • Manufactured by Servomex – over 70 years’ experience pioneering gas analysis and thousands of units used in the field every year



  • Optimized for cryogenic air separation, gas bottling applications or specialty gas laboratories requiring the continuous measurement of N2 in Ar and/or He and also N2 high purity monitoring
  • Control of External Valve Box (via RS232)
  • Three measurement ranges with automatic range change function for optimal output resolution


Easy to use

  • Engineer-friendly, intuitive operation with easy installation
  • Simplified configuration through factory set range options


Low cost of ownership

  • High accuracy PED sensing offers industry-leading reliability, maximizing device uptime and process efficiency
  • Maintenance-free solution providing considerable ongoing cost reductions


Benchmark compliance

  • Electrical safety to IEC 61010-1
  • In compliance with Low Voltage, EMC and applicable Directives




  • Electrical safety to IEC 61010-1: Ed 3
  • Installation Category II IEC 60664-1 Pollution Degree 2 IEC 60664-1
  • In compliance with Low Voltage, EMC and applicable Directives

Schematics (select to expand)


461mm (18.1”) Wide x 132mm (5.1”) High x 484mm (19”) Deep


15kg (33lbs)

Get the detailed specifications

“For in-depth specifications you’ll want to download our technical datasheet which includes information on technology, performance, operating environment, sample conditions and compliance along with technical drawings and top-level benefits and applications.”

Chris Davis
Product Manager

Everything you need to know – download the resource pack

“Our resource pack gives you all the analyzer information you require, including the product brochure and operator manual. See how the Plasma can enhance your process performance.”

Chris Davis
Product Manager

Manuals and brochures

The manual and brochure for the Plasma contain more information about features and benefits, and explain how to install and operate the analyzer. Download them now.

ES Magazine Issue 41 Reliable solutions for industrial gas applications

ES Magazine Issue 41 Reliable solutions for industrial gas applications

SERVOPRO Plasma Product brochure

SERVOPRO Plasma Product brochure

SERVOPRO Plasma Recommended Spares

SERVOPRO Plasma Recommended Spares

See for yourself

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Typical applications

Air separation units

Diverse sensing solutions that adapt to your process

Learn more

Still need to know more? Talk to one of our experts

If you haven’t yet been convinced, then speak to our experts. They’ll give you the best, most knowledgeable explanation of our solutions, and help you find the one that’s most suitable for your application.

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