2635A
Users Manual

A-2

Table A-1. DC Voltage Measurements - Resolution
Range Resolution
Slow Fast
90 mV* 1 µV 10 µV
300 mV 10 µV 0.1 mV
3V 0.1 mV 1 mV
30V 1 mV 10 mV
300V 10 mV 0.1 V
900 mV** 10 µV 0.1 mV
* Not used in Autoranging
*** Computer interface only (see FUNC command).
Accuracy

See Table A-2.

Table A-2. DC Voltage Measurements - Accuracy
ACCURACY ±(%±V)
RANGE 18°C TO 28°C 0°C TO 60°C
90 DAYS
SLOW 1 YEAR
SLOW 1 YEAR
FAST 1 YEAR
SLOW 1 YEAR
FAST
90 mV* .019% + 6 µV .024% + 6 µV .044% + 20 µV .068% + 6 µV .088% + 20 µV
300 mV .018% + 20 µV .023% + 20 µV .040% + 0.2 mV .067% + 20 µV .084% + 0.2 mV
3V .019% + 0.2 mV .024% + 0.2 mV .041% + 2 mV .065% + 0.2 mV .082% + 2 mV
30V .019% + 2 mV .024% + 2 mV .041% + 20 mV .086% + 2 mV .103% + 20 mV
150/300V .019% + 20 mV .024% + 20 mV .041% + 0.2 V .087% + 20 mV .104% + 0.2 V
900 mV* ** .016% + 20 µV .021% + 20 µV .037% + 0.3 mV .064% + 20 µV .096% + 0.3 mV
* Not used in Autoranging.
** Computer interface only (see FUNC command).
Input Impedance

100 Me minimum in parallel with 150 pF maximum for all ranges 3V and below 10 Me

in parallel with 100 pF maximum for the 30V and 300V ranges

Normal Mode Rejection

53 dB minimum at 60 Hz ±0.1%, slow rate

47 dB minimum at 50 Hz ±0.1%, slow rate

Common Mode Rejection

120 dB minimum at dc, 1 ke imbalance, slow rate

120 dB minimum at 50 or 60 Hz ±0.1%, 1 ke imbalance, slow rate