Analog measurement specifications

12 universal (U) terminals individually configurable for voltage, thermocouple, thermistor, current loop, ratiometric, static vibrating wire, and period average measurements, using a 24-bit ADC. One channel at a time is measured.

Voltage measurements

Terminals:

  • Differential Configuration (H/L): U1/U2- U11/U12
  • Single-Ended Configuration: U1 – U12

Input Resistance: 20 GΩ typical

Input Voltage Limits: ±5 V

Sustained Input Voltage without Damage: ±20 VDC

DC Common Mode Rejection:

  • >120 dB with input reversal
  • ≥ 86 dB without input reversal

Normal Mode Rejection: > 70 dB @ 60 Hz

Input Current @ 25 °C: ±2 nA typical

Filter First Notch Frequency (fN1) Range: 5 Hz to 93 kHz (user specified)

Analog Range and Resolution:

 

Differential with input reversal

Single-ended and differential without input reversal
Notch
frequency
(fN1) (Hz)		 Range1
(mV)		 RMS
(µV)		 Bits2 RMS
(µV)		 Bits2
15000 ±5000
±1000
±200		 20.0
4.0
1.6		 19
19
18		 30.0
5.5
1.8		 18
18
17
50/603 ±5000
±1000
±200		 1.2
0.24
0.10		 23
23
22		 5.0
1.1
0.24		 20
20
20
5 ±5000
±1000
±200		 0.60
0.12
0.05		 24
24
23		 4.9
1.0
0.22		 20
20
20

1 Range overhead of ~5% on all ranges guarantees that full-scale values will not cause over range

2 Typical effective resolution (ER) in bits; computed from ratio of full-scale range to RMS resolution.

3 50/60 corresponds to rejection of 50 and 60 Hz ac power mains noise.

Accuracy (does not include sensor or measurement noise):

  • 0 to 40 °C: ±(0.04% of measurement + offset)
  • –40 to 70 °C: ±(0.06% of measurement + offset)
  • –55 to 85 °C (XT): ±(0.08% of measurement + offset)

Voltage Measurement Accuracy Offsets:

  Typical offset (µV RMS)
Range (mV) Differential
with input reversal		 Single-ended or differential
without input reversal
±5000 ±10 ±40
±1000 ±5 ±12
±200 ±2 ±6

Measurement Settling Time: 20 µs to 600 ms; 500 µs default

Multiplexed Measurement Time:

These are not maximum speeds. Multiplexed denotes circuitry inside the data logger that switches signals into the ADC.

Measurement time = INT(multiplexed measurement time • (reps+1) + 2ms

  Differential
with input reversal		 Single-ended or differential
without input reversal
Example fN11 (Hz) Time2 (ms) Time2 (ms)
15000 2.8 1.4
60 36 18.1
50 42.07 21.3
5 402.7 201.4

1 Notch frequency (1/integration time).

2 Default settling time of 500 µs used.

See also Voltage measurements.