NI-9238 Specifications

Definitions

Warranted specifications describe the performance of a model under stated operating conditions and are covered by the model warranty.

Characteristics describe values that are relevant to the use of the model under stated operating conditions but are not covered by the model warranty.

  • Typical specifications describe the performance met by a majority of models.
  • Nominal specifications describe an attribute that is based on design, conformance testing, or supplemental testing.

Specifications are Typical unless otherwise noted.

Conditions

Specifications are valid for the range -40 °C to 70 °C unless otherwise noted. All voltages are relative to the AI- signal on each channel unless otherwise noted.

NI-9238 Pinout



Table 1. Signal Descriptions
Signal Description
AI+ Positive analog input signal connection
AI- Negative analog input signal connection

Input Characteristics

Number of channels

4 analog input channels

ADC resolution

24 bits

Type of ADC

Delta-Sigma (with analog prefiltering)

Sampling mode

Simultaneous

Internal master timebase (fM)

Frequency

12.8 MHz

Accuracy

±100 ppm maximum

Data rate range (fs) using internal master timebase

Minimum

1.613 kS/s

Maximum

50 kS/s

Data rate range (fs) using external master timebase

Minimum

390.625 S/s

Maximum

51.36 kS/s

Data rates (fs)

fM÷256n,n=1,2,...,31

Input voltage range (AI+ to AI-)

Nominal

±0.5 V

Minimum

±0.496 V

Typical scaling coefficient

74.506 nV/LSB

Overvoltage protection

±30 V

Input coupling

DC

Input impedance (AI+ to AI-)

>1 GΩ

Table 2. Accuracy
Measurement Conditions Percent of Reading (Gain Error) Percent of Range[1]1 Range equals 0.5 V. (Offset Error)
Calibrated Maximum (-40 °C to 70 °C) ±0.20% ±0.06%
Typical (23 °C ±5 °C) ±0.07% ±0.005%
Uncalibrated[2]2 Uncalibrated accuracy refers to the accuracy achieved when acquiring in raw or unscaled modes where the calibration constants stored in the module are not applied to the data. Maximum (-40 °C to 70 °C) ±1.8% ±0.3%
Typical (23 °C ±5 °C) ±0.7% ±0.1%

Input noise

3.9 μV RMS

Stability

Gain drift

±7 ppm/°C

Offset drift

1.3 μV/°C

Post calibration gain match (ch-to-ch, 20 kHz)

100 mdB maximum

Phase mismatch (ch-to-ch, 20 kHz)

0.13°/kHz maximum

Phase mismatch (module-to-module, maximum)

(0.13°/kHz · fin) + (360° · fin/fM)

Phase nonlinearity (fs = 50 kS/s)

0.12° maximum

Input delay

405512/fs+3.5μs

Passband

Frequency

0.453 · fs

Flatness (fs = 50 kS/s)

0.11 dB peak-to-peak maximum

Stopband

Frequency

0.547 · fs

Rejection

100 dB

Alias-free bandwidth

0.453 · fs

-3 dB bandwidth (fs = 50 kS/s)

24.6 kHz

Crosstalk (0 kHz to 24.6 kHz)

-115 dB

CMRR (fin = 60 Hz)

140 dB

Spurious-Free Dynamic Range (SFDR) 1 kHz, -60 dB FS

110 dB

Total Harmonic Distortion (THD) 1 kHz, -1 dB FS

-85 dB

Safety Voltages

Connect only voltages that are within the following limits.

Channel-to-channel isolation
Up to 2,000 m altitude

Continuous

250 V RMS, Measurement Category II

Withstand

1,500 V RMS, verified by a 5 s dielectric test

2,001 m to 5,000 m altitude

Continuous

60 V DC, Measurement Category I

Withstand

1,000 V DC

Channel-to-earth ground isolation
Up to 2,000 m altitude

Continuous

250 V RMS, Measurement Category II

Withstand

3,000 V RMS, verified by a 5 s dielectric test

2,001 m to 5,000 m altitude

Continuous

60 V DC, Measurement Category I

Withstand

1,000 V DC

Division 2 and Zone 2 hazardous locations applications (Channel-to-channel and channel-to-earth ground)

60 V DC, Measurement Category I

Measurement Category

Measurement Category I

Caution Do not connect the product to signals or use for measurements within Measurement Categories II, III, or IV.
Attention Ne pas connecter le produit à des signaux dans les catégories de mesure II, III ou IV et ne pas l'utiliser pour effectuer des mesures dans ces catégories.
Warning Do not connect the product to signals or use for measurements within Measurement Categories II, III, or IV, or for measurements on MAINs circuits or on circuits derived from Overvoltage Category II, III, or IV which may have transient overvoltages above what the product can withstand. The product must not be connected to circuits that have a maximum voltage above the continuous working voltage, relative to earth or to other channels, or this could damage and defeat the insulation. The product can only withstand transients up to the transient overvoltage rating without breakdown or damage to the insulation. An analysis of the working voltages, loop impedances, temporary overvoltages, and transient overvoltages in the system must be conducted prior to making measurements.
Mise en garde Ne pas connecter le produit à des signaux dans les catégories de mesure II, III ou IV et ne pas l'utiliser pour des mesures dans ces catégories, ou des mesures sur secteur ou sur des circuits dérivés de surtensions de catégorie II, III ou IV pouvant présenter des surtensions transitoires supérieures à ce que le produit peut supporter. Le produit ne doit pas être raccordé à des circuits ayant une tension maximale supérieure à la tension de fonctionnement continu, par rapport à la terre ou à d'autres voies, sous peine d'endommager et de compromettre l'isolation. Le produit peut tomber en panne et son isolation risque d'être endommagée si les tensions transitoires dépassent la surtension transitoire nominale. Une analyse des tensions de fonctionnement, des impédances de boucle, des surtensions temporaires et des surtensions transitoires dans le système doit être effectuée avant de procéder à des mesures.

Measurement Category I is for measurements performed on circuits not directly connected to the electrical distribution system referred to as MAINS voltage. MAINS is a hazardous live electrical supply system that powers equipment. This category is for measurements of voltages from specially protected secondary circuits. Such voltage measurements include signal levels, special equipment, limited-energy parts of equipment, circuits powered by regulated low-voltage sources, and electronics.

Note Measurement Categories CAT I and CAT O are equivalent. These test and measurement circuits are for other circuits not intended for direct connection to the MAINS building installations of Measurement Categories CAT II, CAT III, or CAT IV.

Measurement Category II

Caution Do not connect the product to signals or use for measurements within Measurement Categories III or IV.
Attention Ne pas connecter le produit à des signaux dans les catégories de mesure III ou IV et ne pas l'utiliser pour effectuer des mesures dans ces catégories.

Measurement Category II is for measurements performed on circuits directly connected to the electrical distribution system. This category refers to local-level electrical distribution, such as that provided by a standard wall outlet, for example, 115 V for U.S. or 230 V for Europe.

Environmental Characteristics

Temperature

Operating

-40 °C to 70 °C

Storage

-40 °C to 85 °C

Humidity

Operating

10% RH to 90% RH, noncondensing

Storage

5% RH to 95% RH, noncondensing

Ingress protection

IP40

Pollution Degree

2

Maximum altitude

5,000 m

Shock and Vibration
Operating vibration

Random

5 g RMS, 10 Hz to 500 Hz

Sinusoidal

5 g, 10 Hz to 500 Hz

Operating shock

30 g, 11 ms half sine; 50 g, 3 ms half sine; 18 shocks at 6 orientations

To meet these shock and vibration specifications, you must panel mount the system.

Power Requirements

Power consumption from chassis

Active mode

730 mW maximum

Sleep mode

50 μW maximum

Thermal dissipation

Active mode

1.48 W maximum

Sleep mode

0.5 W maximum

Physical Characteristics

Screw-terminal wiring

Gauge

0.05 mm2 to 1.5 mm2 (30 AWG to 14 AWG) copper conductor wire

Wire strip length

6 mm (0.24 in.) of insulation stripped from the end

Temperature rating

90 °C, minimum

Torque for screw terminals

0.22 N · m to 0.25 N · m (1.95 lb · in. to 2.21 lb · in.)

Wires per screw terminal

One wire per screw terminal; two wires per screw terminal using a 2-wire ferrule

Ferrules

0.25 mm2 to 1.5 mm2

Weight

146 g (5.15 oz)

Connector securement

Securement type

Screw flanges provided

Torque for screw flanges

0.2 N · m (1.80 lb · in.)

Calibration

You can obtain the calibration certificate and information about calibration services for the NI-9238 at ni.com/calibration.

Calibration interval

1 year

1 Range equals 0.5 V.

2 Uncalibrated accuracy refers to the accuracy achieved when acquiring in raw or unscaled modes where the calibration constants stored in the module are not applied to the data.