The unit is designed for determining dielectric loss tangent and permittivity of transformer oils and other dielectric fluids according to the IEC 60247 and the corresponding national standards GOST 6581-75.

1. ISO 9001:2008 certified company
Liquid Insulation Dissipation factor and Dielectric Factor
Measurement Unit
TIAR

2. SCOPE OF APPLICATION
The unit is designed for determining dielectric loss tangent and permittivity of
transformer oils and other dielectric fluids according to the IEC 60247 and the
corresponding national standards GOST 6581-75.
It is a fully automatic device that allows testing according to the procedures
defined in these standards, as well as according to the user procedures specified in
the appropriate section of the setup menu..
DESCRIPTION AND OPERATION
Comparison of the main characteristics of TIARwith the corresponding
characteristics of the world's bestsamples.
Parameter TIAR Other manufacturers
Tangent measurement 4 … 1x10−6
4 … 1x10−6
Tan δ measurement
resolution
1x10−6
1x10−6
Measurement rangeof
relative dielectric constantε
1 … 30 1 … 30
resolution 0,01 0,01
Applied measuring voltage
АС, kV.
500 … 2000 V RMS 500 … 2000 V RMS
AC frequency setting range 45 … 65 Hz 50, 60 Hz
Oil temperature
measurement range
10 … 110 ᴼС 10 … 110 ᴼС
Temperature measurement
resolution
0,1ᴼС 0,1ᴼС
Weight Not more than
6 kg
28 kg

3. Table 1 – Primary unit specifications.
no Item Value Note
1 Operating AC voltage, V. 85 - 264
2 Power frequency, Hz 48 – 63
3 Power requirement, VA. Below 250
3 Applied measuring voltage АС, kV. Sinusoidal, 500 -
2000 V actual
4 Tan δ measurement range 0,00001 –1
5 Tan δ measurement resolution 1х10-5
6 Tan δ measurement accuracy +/- 1% of
measurement +
0,00008
7 Measurement range of relative
dielectricconstant ε
1,0 – 15,0
8 Accuracy of ε measurement +/- 1%
9 Electrical capacitance C
measurement range
20 – 1000 pF
10 Accuracy of С measurement +/- 1% + 1 pF
11 Oil temperature measurement
range
20 – 110ᴼС
8 Measuring cell volume, cm3
42
9 Electric capacity of an empty cell 65 – 70 pF
One measurementduration, not
more than
5 minutes
Stability of AC measuring voltage,
not more than
AC unit accuracy
AC frequency setting range 45 – 65 Hz
10 Temperature measurement
resolution, o
С.
0,5ᴼС
11 Inbuiltprinter None
12 Process temperature, o
С 0 - 50
13 Storagetemperature, o
С – 20 to +60
14 Relative humidity, % Up to 90 without
condensation
15 Dimensions, mm ___Х___Х___
16 Weight, not more than

4. SCOPE OF SUPPLY
The scope of supply is listed in Table 2.
Table 2 – Scope of supply
Designation Item Quantity Note
Unit 1
Measuring cell 1
Power cable 1
RS-485 interfacecable 1
RS-485/USBinterface
adaptor
1
USB interface cable 1
Grounding cable 1
Manual 1
Fuses 2
Box 1

5. OPERATION AND COMPONENT DESCRIPTION
The principle of operation is based on measuring the difference in amplitudes and
phases of signals obtained when a test sinusoidal voltage with an effective value of
up to 2 kV is applied simultaneously to the reference capacitor and the object of
measurement, which is the measuring cell of the unit.
The measuring cell of the installation is a metal vessel consisting of two parts
electrically isolated from each other - the inner and outer electrodes, between
which transformer oil or another insulating liquid to be examined is poured.
In fact, the measuring cell is an electrical capacitor, the plates of which are the outer
and inner electrodes. A test voltage is applied to the outer electrode, a useful signal
is taken from the inner electrode.
The amplitude and phase of the signal coming from the reference capacitor are
within the permissible error and are considered constant.
The difference between the amplitudes of the signals taken from the reference
capacitor and the internal electrode of the measuring cell is proportional to the
dielectric constant of the liquid under study. The capacitance of the reference
capacitor and the empty measuring cell are selected so that they are approximately
equal.
The dielectric constant of air is approximately equal to one. The dielectric constant
of the oil is several times that. Thus, when the measuring cell is filled with oil, its
electrical capacitance increases by several times (in fact, up to three times) and,
accordingly, the ratio between the amplitudes of the signals coming from the
reference capacitor and the measuring cell changes by the same factor. This ratio is
calculated by the software and is used to calculate the dielectric constant of the oil.
The phase difference between the signals taken from the reference capacitor and
the internal electrode of the measuring cell characterizes the value of the dielectric
loss tangent. In the ideal case, that is, in the case when both capacitors in the
measuring circuits - the reference capacitor and the capacitor formed by the
measuring cell - have exactly the same physical and electrical properties, the phase
difference will be zero. In reality, the phase difference between the signals from the
reference capacitor and the empty measuring cell will be non-zero. This initial phase

6. difference is measured by the software and stored during instrument calibration.
Subsequently, its value is taken into account when measuring the tangent of the oil.
Physically, the tangent of the dielectric loss angle of an insulating liquid
characterizes the property of this liquid as an insulator. If the insulating liquid was
an ideal dielectric, the active component of its resistance to alternating current
would be zero, the measurement would take into account only the reactive
component and the phase shift between current and voltage when the test voltage
was applied would be 90ᴼ. For a reference capacitor, this phase shift is close to 90ᴼ,
and the remaining difference recorded during the calibration process, as mentioned
above, is taken into account during the measurement.
Since transformer oil or another liquid dielectric is not an ideal insulator, when a test
voltage is applied to the measuring cell, not only a reactive, but also an active
component of the signal arises. Its presence affects the signal amplitude, and also
causes a phase shift between the supplied voltage and the measured current by an
amount different from 90o
. Moreover, the worse the insulating properties of the oil,
the more it is a constant voltage conductor and the greater this phase shift.
The essence of the process of measuring the tangent of the dielectric loss angle is to
measure the phase shift between the signal from the reference capacitor, the phase
of which remains unchanged, and the signal from the measuring cell, the phase of
which depends on the dielectric properties of the liquid under study.
Some factors affecting the tangent of the dielectric loss angle are oil contamination,
its moisture content, the accumulation of substances that appear in the process of
prolonged exposure to high voltage and powerful electric fields in the power
transformer of the oil itself, as well as of the electrically conductive and structural
components of the transformer.
The longer this exposure is, the more physical and chemical contaminants
accumulate in the oil that appear during the operation of the transformer.
The measured value of the dielectric loss tangent, thus, allows one to determine
how long it is possible to use the oil in this transformer without change or
regeneration, which prevents emergency situations during the operation of high-
voltage equipment.

7. The specific criteria for continued use or change of oils and insulating liquids are set
in technical documentation, as well as in the operational documentation regarding
the oil-filled high-voltage equipment.
TIAR DESIGN
The main components of the installation are: housing, measuring cell and
electronic modules.
General view is shown in Figures 1 and 2.
Figure1. General view of the unit from the side of the oil drain pan.
1
2
4
5
67
3

8. Figure2. General view of the unit from the side of the mains connection module.
The following components are shown in the images:
1 – Housing top,
2 – Measuring cell cover,
3 – Measuring cell socket,
4 – Cell cable,
5 – Cell connection socket,
6 – Oil drain pan niche,
7 – Lifting handles,
8 – PC connection cable socket,
9 – Power cable connection module,
10 – Drain opening,
11 – Bottom (bottom cover),
12 – Legs.
1
4
7
12
11
10
11
9
8
2

9. Figure3. Insidestructureof the TIAR, view 1.
4
3
7
62
1
8
5
2
9
10
11
1213
14

10. Figure 4. Insidestructureof TIAR, view 2.
Figure 5. Insideview. Electrical modules.
54
12
7
2
11
17
16
15
19
18
2
13
20

11. The following components are shown in the images:
1 – Housing top,
2 – Connection plate,
3 – Measuring cell cover,
4 – Cell cable,
5 – Cell connection socket,
6 – Measuring cell,
7 – fixing clip,
8 – Oil drain pan niche,
9 – Bottom (bottom cover),
10 – Drain opening,
11 – legs,
12 – electronics module,
13 – power cable connection module,
14 – Lifting handles,
15 – Operation electric module,
16 – Electric module of power supply,
17 – lower part of measuring cell with drain pan,
18 – electric module of measurement,
19 – calibrating capacitor,
20 – high-voltageamplifier module.
The upper part of the unit body (1) plays a load-bearing and protective role. All
internal components of the device are mounted on it, including electronic modules,
low-voltage and high-voltage wiring, as well as the included detachable measuring

12. cell. The housing protects the internal parts of the unit from damage and ingress of
foreign objects and substances, and guards the personnel against electric shock,
since it is made of durable insulating material (plastic).
The measuring cell cover (2) has a protective role. It protects the measuring cell
from the ingress of foreign objects and substances during the operation of the unit.
The openings in the cover allow access to the filling openings of the cell through
which oil is poured. For this purpose, the lid has a rotary part with holes that open
access to the filler openings in the “open” position, to pour the oil sample into the
cell and close them in the “closed” position when measuring, and when the device is
switched off. The cover has a two-layer structure. The inner part of the cover is
made of metal, which ensures electromagnetic shielding of the measuring part of
the cell and prevents the penetration of interference arising from the operation of
the unit into the ambient space. The outer part of the cover is made of plastic,
which protects personnel from touching the metal parts of the installation which
could potentially be under operating voltage
The measuring cell socket (3) is designed to connect the communication cable
between the cell and the electronic modules of the unit.
The cell communication cable (4) is designed to communicate the following signals
with the electronic modules of the unit:
- General signal,
- Thermal sensor digital signal,
- General measurement signal,
- Inner electrode measuring signal,
- Motor 1 control signal,
- Motor 2 control signal,
- Heater input current,
- Heater output cover.
The cell cable connector (5) is located on the unit casing and is designed to connect
the cell cable to the unit electronic modules.
The oil drain tray niche (6) is located in the lower part of the body and serves to
install the oil drain tray. The oil drain tray is used to collect the oil used during the
tests. As it is filled (preferably after each test), it should be removed by the operator,
the oil from it should be drained into a container for used oil and the tray should be
inserted back into place. It is recommended to wash the tray from time to time
under warm water using detergents.

13. The handles for lifting the unit (7) are integrated into the body of the unit and are
used to move the unit on the workbench or to carry it over short distances within
the laboratory. It is recommended to move the unit outside the laboratory in a
packing container to avoid damaging it.
The PC communication socket is designed to connect an RS-485 serial cable to the
unit for information exchange between the unit and a PC via an RS-485 - USB
interface converter, which is located a short distance from the computer. The RS-
485 interface allows information to be transmitted over a distance of up to several
tens of meters, making it possible to place the controlling computer at a
considerable distance from the unit. Accordingly, the interface cable can be up to 10
meters long, or even more at customer request.
The power cable connection module is designed to connect a standard power cable
to the device. For this, the module has a standard power plug. In addition, the
module includes a power on / off switch and an EMC-compliant surge protector.
The drain hole (10) is designed to drain the remaining oil when there is no oil drain
tray. This does not normally happen, however, if you remove the tray too quickly
after draining the oil from the measuring cell, oil may continue to drip from the cell
drain hole. The drain hole prevents accumulation of oil residueinside the unit, which
can lead to internal contamination and, ultimately, failure. If oil residue drops on the
surface, where the unit is placed, through the drain hole, it is recommended to
move the unit aside and wipe the surface with a clean dry cloth. To avoid such a
situation, it is recommended that after draining the oil from the cell the operator
wait 20-30 seconds before removing the drain tray.
The bottom of the unit or the bottom cover (11) plays a double role. First, it protects
the unit frombelow fromthe ingress of foreign objects and substances and protects
personnel from accidentally touching energized parts of the unit. Just as the upper
part of the case, the bottom is also made of durable insulating plastic. In addition, if
there is a need for repair or preventive inspection of the unit, access to the internal
parts of the unit is possible after unscrewing the fastening screws and removing the
bottom cover. It is imperative to know that this is allowed ONLY for the
representatives of the manufacturing company or persons authorized by the
manufacturer the manufacturer. Any incompetent intervention in the operation of
the unit can lead to its failure or injury.
Legs (12) are fixed on the bottom (bottom cover) of the body and are designed to
hold it securely, withoutslipping, on the surface whereit is placed.

14. Photos