INS8800 Rev. D 21
Protimeter MMS2 Instruction Manual
5. Diagnostic Procedure Guidelines (cont.)
Item 1: The Search and Measure modes (pinless and pin) should be used in
combination to map out the extent of a moisture problem and to distinguish
between surface and sub-surface moisture. The profile of readings obtained
will give insight into the potential cause (e.g., condensation, lateral ingress or
rising dampness) of a moisture-related problem.
Far greater insight will be obtained from moisture readings taken in a
methodical manner than from those taken in a random manner. When testing
walls, the user should start by taking readings at the lower levels and move up
the wall in regular steps of 4-6 in. (10-15 cm). When high subsurface relative
readings are obtained in the Search mode, the user is strongly recommended
to quantify these values in %WME terms by using the deep wall probes in the
Measure mode. If the depth of clearance holes is increased incrementally by a
nominal 0.4 in. (10 mm) at a time, the moisture profile through the wall can be
established.
Item 2: Condensation related moisture problems are common. When assessing
the risk of condensation, or confirming its existence, the proximity of the
actual temperature of the surface under investigation to the dew point must be
established. The TDIFF measurement in CONDENSATOR mode tells the user
how many degrees the temperature of a surface is above or below the dew
point.
As many condensation situations are transient, TDIFF readings should be taken
in a methodical and regular manner, similar to moisture meter readings in
materials. Ambient RH and temperature values should also be taken to assess
the moisture condition of the room as a whole. Dwellings and working
environments generally have an RH from 40% to 60%, so there may be cause
to investigate environments that register RH values outside this range.