Model 973-SF₆

fOR SF₆ purity & SO₂ concentration in SF₆ gas insulated SWITCHGEARS

The MBW CALIBRATION™ MODEL 973-SF₆™ is an advanced SF₆ gas analyzer for the measurement of humidity, SF₆ purity and SO₂ concentration in SF₆ gas insulated switchgears (GIS) and other high voltage equipment. With its internal gas containment and recovery system, the 973-SF₆ provides a high quality and environmentally safe measurement solution within a single self-contained unit.

Pure SF₆ is the standard filling within GIS, but over time gas compartments become contaminated with water vapor (H₂O) through permeation and by desorption from internal materials. Whilst water vapor and SF₆ do not normally react with each other, in the presence of a high-energy discharge, hydrogen and oxygen disassociated from water vapor will react with the sulfur and fluorine from SF₆ to form decomposition by-products. These include sulfur dioxide (SO₂) and hydrofluoric acid (HF) that are corrosive to the internal components of gas compartments. SF₆ with low water vapor content (low humidity) significantly reduces the potential for formation of these corrosive compounds, which is why accurate and repeatable measurement data is an invaluable part of any GIS preventative maintenance program.

The 973-SF₆ includes:

Transport Case 973-SF6
Aluminum shiel with logo MBW (Peli-Case 1610/1620)
Cotton swabs, sterile (10 pieces)
Serial cable DBP 3m 1:1 male/female
RS-232/ USB Keyspan Adapter
Hex key for SO₂module
USB stick with 973-SF6 software and operation manuals

All accessories can also be ordered separately to replace damaged or missing components.

APPLICATIONS

Electrical power utilities
Gas insulated switchgear
SF₆ gas manufacturers and suppliers

SULFUR DIOXIDE (SO₂)

Sulphur Dioxide is the most common decomposition by-product measured during SF₆ gas quality analysis. Unlike most other decomposition products, it is relatively unreactive once formed, so its concentration remains stable over time, so measurement results are more dependable as a condition assessment parameter.

Since 2012, all our 973-SF₆ MODEL analyzers have been produced ‘SO2 ready’. This means that SO₂ measurement can be easily added during production, or at a later time by the user. Measurement is based on a replaceable electrochemical sensor cell fitted in the gas path close to the sample inlet connection. 0…100 or 0…500 ppm ranges are available.

SO₂ measurement performance is influenced by several factors that in combination can lead to measurement errors. For this reason, measurement accuracy is specified ≤ ±2 % of the measured value. To meet this specification, all SO₂ sensors for use with the 973-SF₆ are individually calibrated in gravimetrically prepared SF₆/SO₂ gas mixtures at three points over their specified range:

100ppmv range: 0, 10, 100 ppmv
500ppmv range: 0, 100, 500 ppmv

IEC 60376:2018: Specification of technical grade sulfur hexafluoride (SF₆) and complementary gases to be used in its mixtures for use in electrical equipment

To Top

Data Sheet

Data Sheet FR

Manual

Manual FR

Manual DE

Process Insights_MBW Model 573_chilled mirror hygrometer

For a complete range of analytical instrumentation, applications, systems, and service options, we will work to match your needs and budget and provide the optimal, and most stable process analysis solution for your application.