Rotek 800A - 4.0 MAINTENANCE; 4.1 Required Test Equipment; 4.2 Performance Tests

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4. MAINTENANCE
4.1 Required Test Equipment
The equipment required to maintain the Series 800 is listed in Table 4-1. Equipment may be
substituted based upon the equivalence of performance specifications.
4.2 Performance Tests
Performance tests may be used to verify adherence to specification. The performance tests
are conducted with a nominal line voltage ±5%, 50-60 Hertz at a temperature of 23 ± 1°C, at a
relative humidity not greater than 50%. A performance checklist is provided as Table 4-2. This
checklist may be copied and entries made upon it to maintain a record of periodic inspection. The
performance checklist designates a limited number of test points which are believed to verify
specifications.
4.2.1 AC Voltage Accuracy Tests
Arrange the equipment as shown in Figure 4-1. Place the Model 5000 and Thermal Transfer
Standard in Standby. Select a DC voltage on the Model 5000 equal to the AC voltage being
calibrated. Set the Series 800 for the voltage to be measured, referring to Table 4-2, Voltage
Accuracy. Select the appropriate voltage setting on the Thermal Transfer Standard, place the Model
5000 and Series 800 in Operate; switch the Thermal Transfer Standard to the DC mode adjusting the
controls for a null. Switch to the AC mode and observe the error of the Series 800 on the Thermal
Transfer Standard directly. Place the Thermal Transfer Standard in Standby. Repeat the above
procedure for the other voltage settings listed in Table 4-2, Voltage Accuracy.
CAUTION
If a four wire system is not going to be employed, make sure that the
test leads connecting the equipment to the Transfer Standard
are of sufficient gage to prevent errors due to lead voltage drop.
4.2.2 Current Accuracy Tests
Currents can be measured using the equipment and procedures of Paragraph 4.2.5, Power
Measurements, and the Series 800 set to unity power factor. In this case the power measurement is
the product of the voltage setting and the current setting, V×I. For each I there is a unique power
output, for a known V. This power measurement can be used as a measure of I.
Set the Series 800 for the current to be measured, referring to Table 4-2, Current Accuracy.
As an example, set the calibrator to 100V, 100VA, 1A, 1 PF, 50Hz in the circuit of Figure 4-4. If the
voltage is exactly 100V, the output of the watt converter is 10 × 100VA/120VA = 8.3333 volts
±0.125% (8.343-8.323). If the voltage is low, say by 0.01%, the output voltage of the watt converter
must be multiplied by 1.0001 to determine current, and vice-versa if the voltage is higher than the
nominal. Repeat the above procedure for the other current settings listed in Table 4-2, Current
Accuracy.