NI 9211 - User Manual

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Summary

NI 9211 Calibration Procedure

Software Requirements

Install NI-DAQmx 9.2+ and select application software support for calibration.

Supporting Documentation

Lists manuals and help files for NI 9211, NI-DAQmx, and application software.

Recommended Test Equipment

Details equipment like calibrators and chassis required for verification and adjustment.

Test Environment Conditions

Specifies required ambient temperature, humidity, and connection practices.

Initial Setup Steps

Guide to install NI-DAQmx, connect hardware, and perform initial checks.

Performance Verification

Procedure to verify NI 9211 operation using specified test points.

Accuracy Verification Procedure

Steps to determine the NI 9211's As-Found status via calibrator measurements.

Adjustment Procedure

Outlines the sequence of operations required to adjust the NI 9211.

Accuracy Adjustment

Procedure to adjust the accuracy performance of the NI 9211.

EEPROM Update

Information on updating the NI 9211 internal calibration memory (EEPROM).

Re-Verification

Repeat verification steps to determine the As-Left status after adjustment.

Accuracy Under Calibration Conditions

Accuracy table based on calibrated scaling coefficients stored in onboard EEPROM.

Where to Go for Support

National Instruments website and contact information for technical support.

Summary

NI 9211 Calibration Procedure

Software Requirements

Install NI-DAQmx 9.2+ and select application software support for calibration.

Supporting Documentation

Lists manuals and help files for NI 9211, NI-DAQmx, and application software.

Recommended Test Equipment

Details equipment like calibrators and chassis required for verification and adjustment.

Test Environment Conditions

Specifies required ambient temperature, humidity, and connection practices.

Initial Setup Steps

Guide to install NI-DAQmx, connect hardware, and perform initial checks.

Performance Verification

Procedure to verify NI 9211 operation using specified test points.

Accuracy Verification Procedure

Steps to determine the NI 9211's As-Found status via calibrator measurements.

Adjustment Procedure

Outlines the sequence of operations required to adjust the NI 9211.

Accuracy Adjustment

Procedure to adjust the accuracy performance of the NI 9211.

EEPROM Update

Information on updating the NI 9211 internal calibration memory (EEPROM).

Re-Verification

Repeat verification steps to determine the As-Left status after adjustment.

Accuracy Under Calibration Conditions

Accuracy table based on calibrated scaling coefficients stored in onboard EEPROM.

Where to Go for Support

National Instruments website and contact information for technical support.

The NI 9211 is a calibration procedure document that outlines the steps for verifying and adjusting the performance of the National Instruments 9211 module. This document is essential for maintaining the accuracy and reliability of the NI 9211 in various test and measurement applications.

Function Description

The primary function of the NI 9211 calibration procedure is to ensure that the NI 9211 module operates within its published specifications. This involves a two-part process: performance verification and accuracy adjustment.

Performance Verification: This step determines the "As-Found" status of the NI 9211. It involves connecting the module to a high-precision calibrator and acquiring samples at specified test points. The average samples are then compared against predefined test limits to ascertain if the module is performing correctly. This verification process helps identify any deviations from the expected performance before any adjustments are made. The procedure details how to configure an AI voltage channel, set timing parameters, and acquire/average samples for each channel.
Accuracy Adjustment: If the verification process reveals that the NI 9211 is not meeting its specifications, an adjustment procedure is performed. This involves using a calibrator to provide precise reference values to the module and then calling an adjustment function within the NI-DAQmx software. The adjustment process updates the internal calibration memory (EEPROM) of the NI 9211, ensuring that its measurements are accurate. The document specifies the reference value to be used for adjustment and the physical channels involved.

Usage Features

The NI 9211 calibration procedure is designed for users who need to maintain the accuracy of their NI 9211 modules. Key usage features include:

Clear Step-by-Step Instructions: The document provides detailed, numbered steps for both verification and adjustment, making it easy for users to follow the procedure. Each step is clearly articulated, from installing necessary software to connecting hardware and executing software commands.
Hardware Setup Guidance: It includes specific instructions for setting up the hardware, such as connecting the NI cDAQ-9178 chassis to the system safety ground, installing the module in the correct slot, and connecting the power source. This ensures a stable and safe environment for calibration.
Software Configuration Details: The procedure outlines the necessary software installations (NI-DAQmx) and configurations, including how to create and configure AI voltage channels and set timing parameters for data acquisition. It also guides users on launching Measurement & Automation Explorer (MAX) and performing a self-test.
Environmental Conditions: The document emphasizes the importance of maintaining specific environmental conditions (ambient temperature, relative humidity) and connection practices (short, shielded copper wires, twisted-pairs) to minimize noise and thermal offsets, which can affect measurement accuracy.
Reference to External Documentation: It directs users to other relevant NI documentation, such as "NI cDAQ-9174/9178 Quick Start," "NI 9211 Operating Instructions and Specifications," and various NI-DAQmx help files, for more in-depth information on hardware setup, specifications, and software programming.
Support Information: The document provides comprehensive information on where to find technical support, including the NI website, corporate headquarters contact details, and phone numbers for assistance in the United States and internationally.

Maintenance Features

The NI 9211 calibration procedure itself is a key maintenance feature, ensuring the longevity and reliability of the NI 9211 module.

EEPROM Update: After an adjustment, the NI 9211's internal calibration memory (EEPROM) is immediately updated. This ensures that the new calibration coefficients are stored and used for future measurements. The document also mentions that users can update the calibration date and onboard calibration temperature without making adjustments, by initializing an external calibration, setting the C Series calibration temperature, and closing the external calibration.
Re-Verification: Following an adjustment, users are instructed to repeat the verification section to determine the "As-Left" status of the device. This crucial step confirms that the adjustment was successful and that the module now meets its specifications.
Troubleshooting Guidance: In case of re-verification failures, the document advises users to recheck the "Test Conditions" and refers them to "Where to Go for Support" for assistance, providing a clear path for resolving issues.
Accuracy Under Calibration Conditions: The document provides a table detailing the gain error and offset error under calibrated scaling coefficients, which are stored in the onboard EEPROM. This information is valuable for understanding the module's performance characteristics after calibration and under specific operating conditions (ambient temperature, chassis slot placement).
Regular Calibration Schedule: While not explicitly stating a schedule, the existence of this calibration procedure implies the necessity of regular calibration to maintain the module's accuracy over time, aligning with the "1-Year Limits" mentioned in the test limits table.
Detailed Equipment List: A recommended equipment list, including a specific calibrator model (Fluke 5520A), chassis (NI CDAQ-9178), and connection accessory (NI 9932), along with their requirements, ensures that users have the correct tools for accurate calibration. This helps in standardizing the calibration process and achieving consistent results.

NI 9211 Specifications

General

Number of Channels	4
Resolution	24 bits
Connectivity	NI CompactDAQ, NI CompactRIO
Operating Temperature Range	-40 °C to 70 °C
ADC Resolution	24 bits
Input Range	±80 mV
Isolation	Channel-to-earth ground
Connector Type	Screw terminal
Storage Temperature	-40 °C to 85 °C
Relative Humidity	10% to 90% RH, noncondensing
Input Type	Thermocouple
Sample Rate	14 S/s
Sampling Rate	14 S/s per channel
Accuracy	±0.3 °C
Temperature Sensor Compatibility	J, K, T, E, N, B, R, S
Isolation Voltage	60 VDC
Shock	30 g
Vibration	5 g
CJC Sensor	Integrated cold-junction compensation (CJC) sensor