trafag TMT501, TMT502 Instruction Manual

Trafag Italia Srl Via Cremona 1

20025 Legnano (Mi)

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INSTRUCTIONS MANUAL

BIMETAL THERMOMETERS

Instruction H21017a 05/2017

BIMETAL THERMOMETERS

TYPE: TMT501, TMT502

1 GENERAL WARNINGS

1.1 Instruments measuring range

Verify that measuring range of the instrument is suitable with wor­king conditions of the circuit/plant. Maximum process temperatu­re must remain within the instrument measuring range, identified
on dial with two black triangles.

1.2 Admitted over temperatures

Accidental over temperatures are admitted for short periods, provi­ded that they remain within the values indicated in the datasheet.

1.3 Ambient temperature

Instruments are designed to work with an ambient temperature
between -20°C/+60°C (-4°F/+140°F). Different ambient tempera­tures could give wrong indications or to damage the instrument. IT
is recommended to verify that the instrument installation position
is not subject to direct heat sources, both for convention or radia­tion: if this is not possible, please foresee a protective screen.

1.4 Mechanical vibrations

Verify that chosen position for the installation is not subjected to
continuous mechanical vibrations, because this will cause accuracy
errors and shorter working life of instrument. If this is not possi­ble, it is recommended to use instruments filled with dampening
liquid.

2 INSTALLATION

2.1 Process installation

The thermometers must be installed in a thermowell that is sui­table to the line or to the tank where the temperature is to be me­asured. It is also necessary to verify that the thermowell is suitable
for the installation of the thermometer. With reference to the figu­re N° 3 is necessary to verify that:

■ The minimum length “S” (see under table 3) guarantee that the

sensing element is totally immerged into dimension of ther­mowell and consequently into the piping, for best sensibility.

■ Bulb diameter d must be maximum 1mm less than the bore

diameter of thermowell.

■ Thermowell thread must be suitable with thermometer thread.

Then insert the instrument bulb till the bottom of thermowell,
screw the rotating connection of thermometer on thermowell
thread and orient the instrument in a position that permit an easy
reading. Then tighten with suitable key the rotating nut and verify
the solidity of the mounting.

NOTE: In the event that the tolerance between bulb diameter and
bore diameter of thermowell is more than 1mm fill the thermowell
bore with suitable transmission fluid such as silicone oil or graphi­te dust : this will improve the instrument performances.

3 Regulation of the instrument in
“every angle” version

Instrument case could be oriented before installation to the requi­red inclination, up to a maximum of 90°. To do this it is necessary to
unscrew the two “A” screws, place the case in the required inclina­tion and then screw again the two “A” screws. (see Fig. 2)

Fig. 2 – Regulation of case inclination

WARNING Absolutely do not use the instrument case to tighten it
on thermowell. This can cause damages to the instrument.

A

2/2

H21017a

BIMETAL THERMOMETERS

TYPE: TMT501, TMT502

4 CALIBRATION AND CHECK

As good practice, is better to make a complete check of the instru­ments twice per year.
The calibration check is normally made by using suitable thermo­static bath and test instruments.
Check is carried out by checking the accuracy on the main divisions
of the dial. Proceed as follow:

■ Insert both the thermometer bulb and the test instrument into

a stable and uniform thermostatic bath.

■ Verify that immersion length of both instrument into the ther-

mostatic bath are the same.

■ Wait for three minutes for a table indication, then verify that

thermometer shows the same temperature of test instrument,
with foreseen tolerance.

■ Regulate, if necessary, the instrument indication using the ex-

ternal micrometric adjustment on the back side of the case or, in
some cases, using the micrometric adjustment on the pointer.

■ Then remove the thermometer from thermostatic bath.

Figure 3 and table of minimum bulb diameters and length “S” are
in mm

5 MAINTENANCE

The instrument doesn’t need any particular maintenance.
Do not lubricate the moving parts because this could attract dust
and form particles and impurities that could produce malfunctions
or accuracy errors.

6 DISMOUNTING AND DISPOSAL

The instrument is essentially made in stainless steel. Therefore,
after removing transparent, gasket, plugs and after removing all
the process fluid traces from the wetted parts (especially if fluid is
dangerous for persons or environment) the instrument could be
recycled or scrape.
Dispose of instrument components and packaging materials in an
environmentally compatible way and in accordance with the coun­try-specific waste disposal regulations.

0... 60 150 135 130

0...80 135 110 105

0...100 115 110 105

0...120 110 100 95

0 ...160

100 90 90Up to

0...500

RANGE °C

Stem Ø

6 or 6.4

Stem Ø
8 or 10

Stem Ø

12

WARNING

In event of accidental breaking of instrument transparent, it is ne­cessary to replace it immediately, taking care of removing all the
small pieces from the case.

Documents Instructions H21017 www.trafag.com/H21017

Data sheet H20017 H20018 www.trafag.com/H2001X

Additional information