47113964.2.023РЭ
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3.4 Verification
3.4.1 External examination
3.4.1.1 Correspondence of the transducer to the following requirements must be determined by
external examination procedure:
-
absence of mechanical failures of the case, cover, latch and terminals set on the cover;
-
well-defined marking;
-
presence of a seal and certificate of calibration.
3.4.2 Testing of the insulation resistance
3.4.2.1 For electrical insulation resistance test fixed voltage (500
±
50) V should be applied be-
tween terminal groups connected together in accordance to table 12.
Table 13
Tested circuits
Numbers of terminals
connected together
Test voltage (RMS), kV
one side
other side
Normal condi-
tions
Highest value of
the humidity
Between current and voltage cir-
cuits
1-2-3-4-5-6
9-10-11-12
2.5
1.5
Between separate current circuits
1-2
3-4-5-6
2.5
1.5
3-4
5-6
2.5
1.5
Between the supply and all others
circuits
7-8
1-2-3-4-5-6-9-10-
-11-12-14-15-16-
-Х2 (1-2-3-4)
2.5
1.5
Between input and output cir-
cuits
14-15-16-
Х2 (1-2-3-4)
1-2-3-4-5-6-
-9-10-11-12
2.5
1.5
Between separate output circuits Х2 (1-2-3-4)
14-15-16
0.5
0.3
Between the case and all circuits Case*
All
2.5
1.5
* The mounting rail simulator fixed on the latch
Take megohmmeter readings on expiry of 1 min after voltage test or when readings established.
3.4.2.2 Result of testing is satisfactory if the value of an insulation resistance isn’t less than 40 M
Ω
.
3.4.3 Intrinsic error testing
3.4.3.1 The intrinsic error is defined by a comparison method of measured parameter with a
known value parameter reproduced by the standard instrument.
3.4.3.2 Intrinsic error of currents, voltages and powers is defined for three-wire and four-wire
connection of the transducer.
3.4.3.3 It is admitted to carry out calibration of intrinsic error only for a measurement mode in
which the transducer is used, if there is a decision of the head of a department of calibration or direc-
tor of firm.
3.4.3.4 The intrinsic error (
γ
) expressed by formula
