Chauvin Arnoux C.A 847 Manual De Instrucciones página 8

The C.A 847 materials moisture meter is designed to measure the level of
moisture in wood.
The measurement principal is as follows: an electric current is passed through
the two electrodes in order to measure the impedance variation due to the
moisture in the material. The instrument immediately translates the measure-
ment into a humidity %.
For wood, the instrument gives a direct reading of the level of moisture in the
wood, expressed as a % of H
For other construction materials, the instrument determines the wood moisture
equivalent (WME).
2. GENERAL COMMENTS ON
MOISTURE IN MATERIALS
Moisture meters are generally calibrated for wood which is the construction
material with the best-known moisture levels, over and above which the material
starts to deteriorate.
In fact, under a level of around 16%, wood is considered dry and will not dete-
riorate (no rot, retention of mechanical qualities, etc.).
Between around 16 and 19%, the acceptable amount of moisture is reached
and signs of deterioration may start to appear.
Finally, over and above 20%, the wood is considered to be damp and signs of
deterioration will obviously appear in time unless measures are taken to reduce
the level of moisture.
For other materials, a wood equivalence is used by establishing the WME (wood
moisture equivalent) which is the level of moisture reached by wood, equal to
that of the material being measured.
Interpretation of the measurement is facilitated since the threshold percentage for
transition from a "dry" to a "humid" condition is the same: between 16 and 20%.
1 Measurement prods to be inserted into the material.
2 Protective cover (protects the prods and switches the instrument off).
3 "ON" light which shows when the instrument is on or off.
4 "LOW BATT" light, which indicates when the battery is low.
5 20 moisture level indicator lamps.
6 Scale graduated as a % of moisture in wood or W.M.E., associated with
a coloured barchart that shows the difference between a dry and humid
condition.
7 Lamp indicating a level of > 23%.
8 When indicator lamp 7 is lit, you should press the red button to obtain a
correct reading.
1. PRESENTATION
O between 6% and 100%.
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3. DESCRIPTION
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