KEY FEATURES

Sig Sulphide Test

The Sig Sulphide test is used to detect the presence of micro-organisms that can generate corrosive sulphide e.g. Sulphate Reducing Bacteria (SRB).

The test can be used to test samples of:

• Process Water
• Bilge Water
• Ballast Water
• Fuel Tank Bottom Water
• Metal Working Fluids
• Lubricants
• Environmental Waters

Metal surfaces which are prone to attack by SRB can also be tested. A swab can be used to swab surfaces or corrosion pits and the swab is then thrust into a Sig Sulphide tube.

The test consists of a screw capped, glass tube half filled with a selective microbiological culture medium that semi-quantitatively indicates the presence of sulphide generating bacteria by the rate and extent of the development of a black colour. Sample is added to the tube which is kept warm (incubated) for up to seven days; results are examined regularly.

The test has been calibrated against the standard Test Method for SRB, NACE TMO-194-94, using American Petroleum Institute (API) Medium.

Sig Nitrite Test

The Sig Nitrite test is used to detect the presence of nitrite reducing micro-organisms in:

• Cooling Waters
• Metal Working Fluids
• Effluent & Waste Waters
• Systems with Nitrite Corrosion Inhibitor

The Sig Nitrite test can be used to confirm that in systems where nitrate is added to inhibit microbial sulphide generation, a suitable microbial population is present. Sig Nitrite tests can be used to confirm that de-nitrification is taking place in effluents, sewage etc.

Nitrite is commonly used as a corrosion inhibitor in cooling water and some metal working fluids. Some microbes, which normally use atmospheric oxygen have the ability to switch nitrite as an oxygen source. The nitrite is reduced to ammonia or nitrogen gas and the fluid rapidly becomes corrosive. The presence of nitrite reducing micro-organisms can result in the depletion of nitrite corrosion inhibitors.

Nitrite can be used to inhibit sulphide generation by sulphide generating bacteria in some systems. In such cases the presence of nitrite reducing microorganisms is desirable.

The test consists of a screw capped glass tube, half filled with a pale orange coloured selective microbiological culture medium that indicates the presence of nitrite reducing micro-organisms in an aqueous sample by changing colour from pale orange to pink and also producing gas bubbles. Sample is added to the tube, which is kept warm (incubated) for up to 5 days; results are examined regularly.

REAGENT CODES