NSG 438
41
10
Maintenance
Care
The housing can be cleaned with a moist cloth with possibly just a trace of
detergent liquid.
Industrial spirit is also a suitable cleaning agent.
Other solvents are not permitted.
Fuses
The instrument contains no fuses that are accessible to the user.
10.1.
Calibration
Trimming procedures in the NSG 438 are carried out digitally and
automatically. The instrument contains no elements that are foreseen for
adjustment by the user. A component defect must be suspected if the
calibration measurements differ from the published technical data and the
instrument is to be returned to an authorized Schaffner service centre.
Measurements can only be undertaken by trained specialists. A
prerequisite is the availability of the necessary measurement equipment as
listed in section “Verification of pulse data”.
Charge voltage check:
Equipment: EHT voltmeter with 40kV voltage range
Internal resistance > 20G
Ω
.
Measurement accuracy < 1%
Check the voltage level under the following conditions:
Air-Discharge
Single-Discharge
Polarity: positive and negative
Voltage settings: 2, 4, 8, 15 and 30kV
Permissible tolerance < ± 5% of set value
