R. DOROBANTU, DOREL ZUGRAVESCU, D. DELION, ILEANA FATULESCU
Laboratorul de Geodinamica si Analiza Numerica,
Centrul de Fizica Pamantului si Seismologie, Bucuresti
A THERMOGRAPH WITH THERMISTORS FOR GEODYNAMIC OBSERVATORIES
(Abstract)
The thermograph with thermistors tested in the geodynamic laboratory may
be used to equip the underground geodynamic observatories, as well as the complex
geodynamic stations situated on both sides of active faults and intended for
pursuing the time evolution of the geophysical phenomena causally related to
the processes which lead to earthquake triggering.
With some changes of the sensors (their construction and their grouping) and
of the mode of connection with the storage and information display systems,
the apparatus is able to determine the time and space variation of the temperature,
respectively of the temperature gradient in boreholes.
The thermograph with thermistor tested in the geodynamic laboratory allows
to make conspicuous the temperature variations at ten points with an error
less than 10-3°C for the whole temperature range, where the temperature-electrical
resistance transducer may be used.
The thermograph with thermistors was especially devised to equip our underground
geodynamic observatories and the complex geodynamic stations. It was tested
in two variants:
I: the thermograph for the underground type of geodynamic observatory, which
is able to record and to display the numerical value of the temperature with
an error less than 10-3°C (fig. 4) in the temperature range 11° – 13°C;
II: the thermograph for the complex geodynamic stations which is able to record
and to display the numerical value of the temperature with an error less than
10-2°C (fig. 4), in the temperature range 7° – 17°C.
The tested thermograph is able to record continuously, in analog form, the
values of the temperature, respectively their storage, in digital form on a
punch writer (fig. 8) or on a high density support; the thermograph has also
TTL outputs, enabling it to be connected with a real time processing system
of the temperature values.