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Germann Instruments, Inc.
Test Smart – Build Right
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7.
Installing the gaskets with epoxy
Epoxy between the gaskets and the specimen has to be applied if the concrete surface is rough or not
complete cylindrical, or if notches are present from saw cutting, or otherwise, if the cell cannot be made
watertight after assembling.
Preferably, use a two component, moisture tolerant, fast curing epoxy, methacrylate, epoxy-methacrylate
or a similar formulation to avoid long times waiting the adhesive to harden. A creamy consistency is
desirable so that the adhesive is not absorbed by the concrete surface and the sealing effect is lost.
Blot the moistened specimen dry with a piece of cloth and apply the prepared epoxy in a thin layer to the
specimen circumferential surface, up to 10 mm from the end. While the epoxy is still wet, govern the
rubber gasket over the end of the specimen in a rotary motion until it is flush with the specimen end face.
Remove as much as possible of the excess epoxy collected on the rubber gasket by means of a spatula
and/or cloth.
Apply a thin layer of silicone oil to the end faces of the spacer. Position the spacer centrally on the
specimen for it to rest against the gasket. Govern, in the same way with epoxy, the other rubber gasket
over the remaining end of the specimen, again with a rotary motion until the gasket is resting against the
spacer. Remove any excess epoxy and wait until the adhesive has hardened enough to turn this
subassembly upside down. To avoid water evaporation from the ready-made moistened specimen, cover
the specimens with a plastic wrap or sheet and allow the epoxy to harden according to its specifications.
Oil with silicone oil slightly the side faces of the gaskets prior to mounting the gaskets in the cell and
follow the same procedure described in section 6 to complete the cell assembling and fill the chambers
with the testing solutions.
8.
Connecting the cells to the Proove’it
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Microprocessor Power Supply unit
Cell #1 is connected to channel #1 of the power supply unit, cell #2 to channel #2, and so on. A maximum
of 8 cells can be tested simultaneously with the Proove’it
©
Classic.
It is imperative that each cell is connected only to each channel of the power supply binding posts. In
other words, the red jack to the red binding post and the black jack to the black binding post of the same
channel of the power supply unit.
Every cell must be connected to the control unit before turning it on. Otherwise, it might cause a surge in
current that will damage the internal control circuitry. Intermittent current readings on any channel can
also cause the unit internal damage.
If the operator wish to use the supplied temperature probes, place each temperature probe in one of the
holes in the cell half with the black jack, also marked with “°C”. This safeguards the cell if the temperature
of the liquids gets close to 90
o
C by which the system is automatically turned off.
WARNING:
The power supply will suffer irreversible damage if the cords from one cell are crossed with
another channel’s cell.
