SF6 gas measuring devices

A range for all requirements

Measuring instruments are used to monitor ambient air, trace leaks and to measure the SF6 quality of electrical operating equipment.

The SF6 gas must always be pure since humidity and toxic or corrosive decomposition products in circuit breakers impair the insulating properties of the gas.

The gas quality has to be monitored in accordance with the F-gas Regulation (EU) 517/2014. The IEC 60480 directive also stipulates the limit values for the re-use of SF6 gas.

It is absolutely necessary to know the gas quality before carrying out maintenance works on a circuit breaker in order to be able to decide on preparation, re-use or disposal of the SF6 gas.

The essential quality criteria for SF6 gas in circuit breakers are as follows:

  • Humidity (dew point)
  • Decomposition products
  • Gas purity in %

DILO offers a complete range of measuring devices for all applications including: room monitoring systems, leak detectors, measuring devices to determine the SF6 quality as well as relevant accessories for simple on-site measurement and retrofit kits for old measuring devices.



The cordless battery-operated device measures in six sensitivity levels within a very short response time. The device switches automatically to the next higher level of sensitivity for detection of larger leaks.

Sf6 leak detection device

It is possible to switch over the device to the most sensitive measuring range by simply pressing the corresponding key. The SF6 concentration is displayed next to the indication of the measuring range by an LED bar display and an audible signal.

Other features:

  • Quick response time
  • Low “Recovery” time
  • Automatic switching over to levels of sensitivity
  • Detection of leaks of up to 5 g / year
  • Single-handed operation
  • Battery-operated
  • Temperature-compensated


SF6 Multi-Analyser

3-038-R… without return system
3-308R-R… with gas return system

This multi-functional device allows the determination of up to six quality parameters with only one measurement:

  • SF6 concentration (%)
  • Moisture concentration
  • SO2 concentration (ppmv)
  • OPTION: HF concentration, H2S concentration, CO concentration (in ppmv each)

The SF6 Multi Analyser is a user and maintenance-friendly device which guarantees high measuring accuracy.SF6 Gas Multi-Analyser

First of all, the gas is checked for decompositions products. If critical SO2 values are determined the measurement can be interrupted. In case of contaminated SF6 the complete measuring gas can be recovered from the internal vessel. Thus, any contamination of the other sensors is avoided and the functionality of the device is ensured.

If the sensors have to be calibrated they can easily be exchanged by the operator on site. The device is immediately ready for use without loss of time based on the “Plug & Play“ principle.

Other features:

  • No emissions of measuring gas
  • Data transmissionto USB stick
  • Modular interchangeability of the sensors
  • Adjustable user languages: DE, GB, FR, ES, IT, PT, CZ, PL, CN
  • Easy handling and menu guidance via colour touch screen (5.7″)
  • Results of up to 100 measurements can be stored with name, date and time
  • Trolley for comfortable transportation (3-038R-R… version)
Example: Moisture sensor as exchange module

SF6 Air Sensor


The device even detects smallest SF6 concentrations and displays the current measuring values permanently. For the operating personnel it is absolutely necessary to know that no radioactive source is used. Therefore no special measures must be taken during operation.

The SF6 Air Sensor guarantees a quick reaction time. Furthermore, there is no cross sensitivity to moisture and unaffected by background

Indoor SF6 monitoring device

contamination and the measuring result remains constant. Parameters for warning messages and alarm tripping are freely configurable.

Other features:

  • Measuring range: 0 to 1,500 ppmv SF6
  • High longtime stability
  • No maintenance and consumables are required
  • Indication of the measuring value via LCD on the front of the device
  • Air pressure compensated
  • Analogous and serial interface

Important note: The device can only be used together with the SF6 Network Monitor. It cannot be operated autonomously.

Discharge gas collecting bag


This bag is a simple and cost-effective system for collecting measuring gas in case it cannot be returned directly into the circuit breaker. Its handling is very easy: Connect the bag with the hose included in the scope of supply to the measuring device.

The discharge gas collecting bag allows collecting the SF6 from up to 25 measurements. The gas can be removed by means of any service cart. When using this system no SF6 is released into the atmosphere. It is light, practical and environmentally friendly.

Other features:

  • 52 l capacity
  • Light folding bag for comfortable transportation
  • Integrated safety valve (pe = 100 mbar)
  • Self-closing miniature couplings

All DILO measuring devices equipped with a gas return system can be connected to the discharge gas collecting bag (see leaflets of the SF6 measuring devices).

For more information please refer to our technical data sheet.