Number of channels

4

Number of digits

5½ (±199999 counts) ^{[ 1 ]}

Full-scale DC voltage ranges

Range
1
2
3
4

Voltage
±19.9999 V
±1.99999 V
±999.99 mV
±199.999 mV

Resolution
100 µV
10 µV
10 µV
1 µV

Noise, counts rms ^{[ 1, 2 ]}
1.0
0.6
0.6
1.0

Measurement accuracy, ±(% of reading + counts) ^{[ 3 ]}

Range
   1^{[ 4 ]}
2
3
4

24 Hrs., (23 ± 1) °C
0.0004 + 1.5
0.0004 + 2.0
0.0004 + 2.0
0.0004 + 4.0

90 day, (23 ± 5) °C (typ.)
0.0050 + 1.5
0.0050 + 2.0
0.0050 + 2.0
0.0050 + 6.0

1 year, (23 ± 5) °C (typ.)
0.0080 + 1.5
0.0080 + 2.0
0.0080 + 2.0
0.0080 + 6.0

Transfer accuracy

(24 hour counts error)/2 ^{[ 3 ][ 5 ]} (typ.)

Input resistance

10 MΩ ± 1 %,  >3 GΩ selectable on ranges 2 to 4 ^{[ 6 ]}

Input terminals

BNC (Amphenol 31-10 or similar)

Input protection

±60 V center to shield,  ±200 V shield to earth

Triggering

Internal, external (TTL), or remote

BUSY output

TTL logic high when busy

Update rate at line frequency ^{[ 7 ]}

3.6/s (60 Hz),  3.0/s (50 Hz)

Normal mode rejection at
      line frequency

90 dB (59 Hz to 61 Hz or 49 Hz to 51 Hz)

CMRR (at DC)

125 dB (for 1 kΩ unbalance in the shield)

Settling time

1 s to within 3 counts of final reading on ranges 1 to 3, 8 s on range 4

Display

Red LED, 0.40", with polarity indication. Green LED for range and autorange indication

Operating temperature

0 °C to 40 °C, non-condensing

Interface

Serial via SIM interface

Connectors

BNC (4 front, 2 rear)
DB15 (male) SIM interface

Power

Power supplied by the SIM900 Mainframe, or optionally by a user-supplied DC power supply (+5 V)

Dimensions

3.0" × 3.6" × 7.0" (WHL)

Weight

2.3 lbs.

Warranty

One year parts and labor on defects in materials and workmanship

NOTES
[ 1 ] One count is a unit change in the least-significant digit. Greater resolution is available through the remote interface
[ 2 ] Measured over 360 consecutive readings
[ 3 ] Inside SIM900 mainframe following a two hour warmup, autozero ON
[ 4 ] Scale calibration ON
[ 5 ] Within 10 minutes and ±0.5 °C, within ±10 % of the initial value, fixed range, input between 10 % and 100 % of full scale
[ 6 ] Input bias current is <1 pA at 23 °C
[ 7 ] Internal triggering, autozero ON. Rate is double for autozero OFF