Hygrothermographs

In response to Sean Harrison's query regarding the use of
hygrothermographs, the Royal Ontario Museum has been using the ACR
Smartreader 2 dataloggers for some years.  Some are used to monitor
specific situations, such as cold storage, continuously.  Others are
used as needed to provide information on a gallery, shipping crate,
or display case on a short-term basis.

To date we have been very pleased with their performance.  They are
small enough to be placed in a display case without being too
visually obtrusive. The Windows version of the software produces
neat, professional-looking graphs with a colour printer.  A laptop
computer can be used to download the data 'in situ', so that the
dataflow is not interrupted by having to bring the logger to a PC.

It is necessary to keep an eye on the calibration, which inevitably
drifts over time, as indeed it does for most kinds of monitoring
equipment.  We have found it necessary to have some kind of
benchmark or standard with which to compare the dataloggers on a
regular basis.

Less happy experiences include having to put the sheet of paper
through the printer twice in order to print the statistics (high,
low, mean, range) on the same sheet as the graph itself, which is a
nuisance, but nothing more, and the fact that the remote sensor is
fractionally too large to pass through the size of probe-hole which
we chose to be the institutional standard for our display cases,
which may be a difficulty peculiar to this institution, and in any
case is not insurmountable.

Unfortunately I cannot help with the other devices listed, but I
would be glad to discuss the ACR loggers further if required.

Helen Coxon
Conservator
Royal Ontario Museum
Toronto
416-586-5897

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                  Conservation DistList Instance 12:9
                  Distributed: Thursday, July 9, 1998
                        Message Id: cdl-12-9-003
                                  ***