Equipment Required; Calibration Procedure - Metrix GX1010 Notice De Fonctionnement

The crystal in the timebase is pre-aged but a further ageing of up to ±5ppm can occur in
the first year. Since the ageing rate decreases exponentially with time it is an advantage to
recalibrate after the first 6 month's use. Apart from this it is unlikely that any other
parameters will need adjustment.
Calibration should be carried out only after the generator has been operating for at least an
hour in normal ambient conditions.

3.3.1. Equipment Required

• 3½ digit DVM with 0·25% DC accuracy and 0·5% AC accuracy at 1kHz.
• Frequency counter capable of measuring 10·00000MHz and 50µs ±0·1µs pulsewidths.
The DVM is connected to the MAIN OUT and the counter to the AUX OUT.
Frequency meter accuracy will determine the accuracy of the generator's clock setting and
should ideally be ±1ppm.
It may be quicker to use an oscilloscope for steps 05 and 15 (see next section).

3.3.2. Calibration Procedure

The CALibration procedure is accessed by pressing the blue EDIT key followed by CAL,
the shifted function of 6. At each step the display changes to prompt the user to adjust the
rotary control or FIELD/DIGIT keys, until the reading on the specified instrument is at the
value given. The FIELD keys provide very coarse adjustment, the DIGIT keys coarse
adjustment and the rotary control fine adjustment. Pressing CONFIRM increments the
procedure to the next step; pressing CE decrements back to the previous step.
Alternatively, pressing ESCAPE exits to the last CAL display at which the user can choose
to either keep the new calibration values (CONFIRM), return to the old values (ESCAPE) or
restart the calibration procedure (CE).
The first two displays (CAL 00 and CAL 01) specify the connections and adjustment
method. The subsequent displays, CAL 02 to CAL 20, permit all adjustable parameters to
be calibrated. The full procedure is as follows:
CAL 02 Zero DC Offset.
CAL 03 DC Offset +ve full scale.
CAL 04 DC Offset -ve full scale.
CAL 05 Multiplier zero offset.
CAL 06 Waveform offset.
CAL 07 Waveform offset.
CAL 08 Waveform DC offset.
CAL 09 Waveform full scale.
CAL 10 Squarewave full scale.
CAL 11 -20dB attenuator.
CAL 12 -40dB attenuator.
CAL 13 -12dB intermediate attenuator.
CAL 14 -20dB intermediate attenuator.
CAL 15 AM squarewave zero.
CAL 16 AM squarewave full scale.
CAL 17 AM sinewave full scale.
CAL 18 HF squarewave symmetry (50%)
CAL 19 HF squarewave symmetry (75%)
CAL 20 Clock calibrate.
GX1010
Adjust for 0V ±5mV
Adjust for 10V ±20mV
Check for -10V ±20mV
Adjust for minimum
Note reading (DCV)
Adjust for CAL 06 reading ± 10mV
Adjust for 0V ±5mV
Adjust for 10V ±10mV
Adjust for 10V ±10mV
Adjust for 1V ±1mV
Adjust for 0.1V ± 0.1mV
Adjust for 1.768V AC ±5mV
Adjust for 0·707V AC ±1mV
Adjust for minimum output
Adjust for 10V ±10mV
Adjust for 3.54 VAC ±10mV
Adjust for 50µs ± 0.1µs
Adjust for 75µs ±0.1µs
Adjust for 10·00000MHz at MAIN OUT
or 27·48779MHz at rear panel CLOCK
IN/OUT. Adjust to ±1ppm.
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