AMETEK Ls Series - Manual (Page 99)

User Manual Lx / Ls Series
95
6. Calibration
The Routine Calibration should be performed every 12 months. Non-routine Calibration is only
required if a related assembly is replaced or if the periodic calibration is unsuccessful. Calibration
of the Lx/Ls system can be performed from the front panel or over the bus. This section covers
calibration from the front panel.
6.1 Recommended Calibration Equipment
Digital Multimeter: Fluke 8506A or equivalent / better.
HP 34401A or equivalent / better
100 mOhm Current Shunt: Isotek Model RUG-Z-R100-0.1.calibrated to 0.25% - OR -
10 mOhm Current Shunt: Isotek Model RUG-Z-R010-0.1.calibrated to 0.25%
(For single phase mode or multi-chassis Lx/Ls configurations, a
10 mOhm shunt may be needed .
Load Bank: Various high power load resistors or a resistive load bank will be
needed. (E.g. Avtron) Size of the load bank depends on model
and phase mode. A load is required to perform the current
measurement calibration near full scale. Current measurement
calibration should be done on the lowest available voltage
range.
The accuracy and value of the load resistor is not critical as long
as the current drawn is sufficient to operate the AC Source in
the upper current range (80-100 %). Suggested values of load
bank settings are shown in Table 6-1 and Table 6-2.
Phase Meter Krohn-Hite Model 6620 or equivalent phase meter (0.01°
resolution, 0.02° accuracy).
6.2 Calibration Screens
The calibration screens for output or measurement calibration can be selected from the MENU
screen. (Press MENU button several times to toggle to select the CALIBRATION screen.)
To select the CALIBRATION screen press the or key several times to select PASSWORD.
Then press the ENTER key. This will bring up the PASSWORD screen. To prevent unauthorized
access to calibration data, a password must be entered to access any calibration screen. The
calibration password is an numeric value equal to the high voltage range limit, typically 300 on a
Lx Series and 270 on a Ls Series. Units with a
–HV or –EHV output range option may have a
different high voltage range value and corresponding calibration password. Check the serial tag
label or the LIMIT screen when in doubt.
The password can be entered using the Voltage shuttle to dial in the number. Once the correct
value is reached, press the ENTER key. Once set, the calibration screens remain accessible
until the Lx unit is powered down. If you leave the calibration screen and return, toggle the value
up or down and back, followed by the ENTER key to re-engage the calibration mode.
On Lx systems or Ls systems with three-phase output capability, use the PHASE key on the front
panel to select the phase to be calibrated.
To select the MEASUREMENT CALIBRATION screen, follow the same steps as outlined above
but select the MEASUREMENT CAL entry instead of OUTPUT CAL. If another CALIBRATION
screen has been accessed since power-up, no password is needed. Otherwise, enter the same
password as indicated above.