Oxygen meters

for anoxic treatments. To come very soon...

Since absorption of oxygen reduces the volume of the bag by one fifth, bags must always be prepared 20% larger!Low-oxygen storage can considerably extend the lifetime of many materials. The best example is rubber, which by no other means can be stored effectively over long periods. Many plastics also profit from low-oxygen atmoshperes. Corrosion of metals is practically stopped, even in humid and salt infested conditons, as it is the case with fresh archaeological finds which must not be dried. Textiles, paper or film materials also profit from low-oxygen atmospheres, but to a much lesser extent: In the case of these materials, other reaction mechanisms like hydrolysis are much more important than oxydation.

Next to long term-storage of materials, anoxic storage is specially useful for the desinfestation of small and medium-size objects:

Oxygen scavengers ATCO FTM 2000, Ageless-Z
and oxygen indicator Ageless-eye

This oxygen absorber reduces the oxygen concentration in a sealed container to below 0,01% creating a very low-oxygen environment. Ageless sachets contain fine iron powder covered with sea salt and a natural zeolith impregnated with a NaCl-solution. One sachet of Ageless Z 2000 absorbs 2000 ml oxygen (the oxygen from 10 l air)  and contains 7,5 g water which can be controlled by a humidity buffer like PROSORB. With no humidity buffer involved, Ageless creates a relative humidity of 75% RH within the container - ATCO FTM only max 68% RH. The heat of the reaction elevates the temperature within the sachets up to around 42°C.

Ageless should be used at humidites above 55% RH. Below 55% RH, oxygen absorption is slower and activity is reduced. In dry conditions, the RP-types should be used.

Ageless-eye is a small oxygen indicator tablet turning pink below 0,1% oxygen and returning to blue above 0,5% oxygen. Ageless-eye can be stored 6 months in a refrigerator in a sachet containing an oxygen absorber. After more than one year of storage, the color shift is not reliable any more. 

Oxygen scavenger RP-K is also active under dry conditions and is absorbing oxygen without influencing relative humidity. Furthermore it contains some active charcoal for the  adsorption of pollutants like SO2, HCl or NH3 .  RP-K contsists of unsaturated organic compounds and some inorganic sorbents like graphite and Ca(OH)2 as well as polythene. Oxygen scavenger RP-A is containing similar materials but also a very strong sorbent for humidity (zeolith), bringing down relative humidity within the container close to zero. One sachet of RP-5A absorbs around 1,1 g of water. RP-A fights again metal corrosion on three levels, reducing simultanously oxygen, humidity and pollutants. However, for most metal objects in museums, dry storage with desiccants like silica gel or bags of molecular sieves will be sufficient to stop corrosion. from: www.mgc-a.com, click for further information

Containers/bags/sheets:

For smaller items or medium-term appliances, pre-sealed bags are available which can be closed by special clips (prices on request).

PRICES:

Oxygen absorber ATCO FTM 2000, sufficient for 10 l of air (2000 ccm oxygen), gives off only small amounts of water vapour, less than Ageless. Depending on the quantity of hygroscopical materials contained inside the bag the RH inside the bag will only rise slightly. In empty bags the RH inside the bags can rise up to 68% RH. To buffer changes in RH you can add PROSORB sachets. ATCO FTM is only available in this bag size. If you need smaller sachets, you have to use Ageless. 

Ageless ZPT 200 sufficient for 1 l of air (200 ml oxygen). Other bag sizes are available on request, but term of delivery can be up to 3 month.

2) Indicator tablets: (can be kept in the refrigerator for about 6 month, so don’t buy too many at a time).

3) ESCAL film, transparent, sealable oxygen barrier film: oxygen transmission rate only 0,05 ccm oxygen per m²/day!
   Composition: PP/ceramic deposited PVA/PE.  
   Often the most economical solution is to make bags using ESCAL for the front side and aluminium barrier foil for the back side.

For pre-sealed bags or tubes on a roll, please contact our partner m-art (address see below).

4) Aluminium barrier film:
(12 µ polyester, 15 µ aluminium, 100 µ polythene), 1 m large, sealable with an impluse welder or a heat sealer.

5) Impulse welders: 

Impulse welder Polystar Pulse generator Polystar 100 GE, for polythene films up to 2 x 0,3 mm thickness, all sealable barrier foils as well as bubble wrap. With 3 m cable. The power supply for the following sealing pliers: (in stock) €   355,- Sealing plier Polystar 30 D, sealing length 300 mm, sealing width: 3 mm, with  3 m cable, 0,8 kg (in stock) €   310,- Sealing plier Polystar 40 D, sealing length 400 mm, sealing width: 3 mm, with 3 m cable, 0,95kg (in stock) €   312,-

Impulse welder Joke SZ 380 Sealing plier SZ 380, the perfect tool for all sealing jobs, makes 380 mm long and 8 mm wide seals, weight: 2,7 kg Including pulse generator G100, 780 W, 230 V, 7,2 kg. Not the cheapest, but in tests it turned out to be the best for anoxic storage. It also can be rented if you only need it for a short period - price on request

€  1181,-

References

• Elert; K. und Maekawa, S.: "Anwendung von Sauerstoffabsorbern in Museen, Lagerung sauerstoffempfindlicher Materialien, Schädlingsbekämpfung", in: Restauro 5/2000, 348 - 453.
• Gilberg, M. und Grattan, D.: "Oxygen-free storage using Ageless oxygen absorber", in: Preventive Conservation, IIC Congress Ottawa (1994) 177-180. und Ref.
• Gilberg, M.: Inert atmosphere disinfestation of museum objects using Ageless oxygen scavanger", in: ICOM Committee for Conservation, 9th Triennal Meeting, Dresden (1990) 812-816.
• Daniel, Vinod: "Nitrogen Fumigation: A Viable Alternative", ICOM Committee for Conservation 19th Triennal Meeting, Washington (1993) p. 863-867.

Terms of sales and delivery