3% of range within frequency and voltage ranges
3% of range.
(1) Electrical design.
10 megohms for 2 least
sensitive null ranges, all input ranges; 1 megohm for 2 most sensitive null
ranges; all input ranges.
(4) Regulation of reference supply.
(5) Stability of reference supply.
0.0005% peak-to-peak per hour.
0.0007% peak-to-peak per day. 0.0013% peak-to-peak per 60 days.
(6) Stability of instrument.
0.00025% peak-to-peak per 60 days.
5% of null range (3% with
(7) Accuracy of off-null deflection.
voltage dials at zero).
(8) Kelvin-Varley divider accuracy. 0.0012% of setting from 1/10 of
full scale to full scale.
0.0012% terminal linearity below 1/10 full
(9) Recorder output.
Adjustable from 0 to 20 mv minimum for full
scale right and left deflection.
Front panel switch selects DC, -DC and AC.
(11) Warmup time.
dc 30 seconds; ac one minute.
(12) Common mode rejection.
130 db dc; 85 db at 60 Hz; 70 db at 400
Battery operation of Model 887AB provides complete
isolation from power system ground, for elimination of
error due to ground loops.
0C to 50C (see accuracy)).
(13) Operating temperature range.