Documentation-Sampling

<bibimport /> Author: Hans-Jürgen Schwarz
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Abstract

At the beginning of each analysis is a appropiate sampling and documentation. The sampling is the most important prerequisite for a successful investigation for planning appropriate measures. The documentation captures the metadata of the samples and assigns each sample a unique collection site.

Inroduction: Sampling

Each sampling has an interference with the object. In general, at sensitive objects such as wall paintings it should be done by conservators or at least together with a conservator. Essential to the success of research and analysis however is that the analyst is also present on sampling. The accuracy of a subsequent analysis depends directly on how representative the sample for the object , because a sample is not be taken to get an analysis, but to get an answer to a specific question. Therefore, the sample type, size and location must be able to give an answer.

The number of samples depends on the question. Since chemically different salts may occur in the same shape and the same salt efflorescences in different forms, it is advisable to sample each crust or efflorescence. On having probably salt-induced damage it is often advisable to take samples along horizontal, vertical or depth profiles to capture the distribution of the damaging salts in regard to action planning.

Pure salt samples are easier to determine than salt mixtures or contaminated samples. For analysis, the pure salts are removed without their substrate. You need only a very small amount of salt.

In addition to surface samples to answer the question drilling dust [Steiger.etal:1998]Title: Salze in Natursteinmauerwerk - Probennahme, Messung und Interpretation
Author: Steiger, Michael; Neumann, Hans-Herrmann; Grodten, Torsten; Wittenburg, Christian; Dannecker, Walter
or core samples are useful.

If droplets are found on the surfaces, so thess should also be examined to see whether the reason is condensation or a hygroscopic solution.

The time of sampling plays a role, as there is a dependency between the type of crystallizing salts and the climate. This dependency on climate should be documented in the mapping but should also have influence on sampling time and place. The samples should be analyzed immediately after collection to avoid changes to other hydrate phases.

As small sample containers are suitable,you can use water vapor-tight, sealable plastic bags, tubes or little boxes. Gelatin capsules are not suitable for storage of salt-containing samples, since moisture can escape or invade.

Inroduction: Documentation

Sampling should always be documented. To zhis documentaion belong:

• Sampler(for inquiries)
• Sampling time(date, time)
• climatic conditions(e.g. T, RH)
• exact sampling point(Mapping Entry, sketch, photo)
• Description of the sample and the substrate
• Question
• details important for further investigations and interpretation

Literature

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crystallization of a dissolved salt

relative humidity