AEMC INSTRUMENTS Model 6255 Micro-Ohmmeter User Manual

1. Overview

The AEMC INSTRUMENTS Model 6255 is a high-precision Micro-Ohmmeter designed for accurate resistance measurements. It is capable of measuring resistance from 0.1 microhm up to 2500 ohms, with a resolution of 0.1 microhm. This device is suitable for a wide range of industrial and scientific applications requiring precise low-resistance measurements.

Key features include an LCD display, an output current range of 0.1A to 10A, and internal data storage for up to 1500 test results. It is powered by an 8.5Ah NiMH battery, ensuring portability and extended operation.

2. Safety Information

Before operating the AEMC Model 6255, please read and understand all safety instructions. Failure to comply with these instructions may result in electric shock, fire, or damage to the instrument.

• Always ensure the instrument is in good working condition before use.
• Do not use the instrument if it appears damaged or if the insulation on test leads is compromised.
• Observe all local and national safety codes.
• The instrument is rated IEC/EN 61010-1 CAT III 50V Pol 2. Adhere to these safety categories during operation.
• Do not attempt to measure resistance on live circuits unless specifically designed and rated for such applications.
• Use only accessories and test leads supplied or recommended by AEMC INSTRUMENTS.
• Keep the instrument dry and clean. Avoid exposure to extreme temperatures or humidity.

3. Product Components and Features

The AEMC Model 6255 Micro-Ohmmeter comes with the following items:

• AEMC INSTRUMENTS 6255 Micro Ohm Meter
• Necessary test leads (not explicitly listed in "whats_in_the_box" but implied for operation)
• Power adapter/charger (for NiMH battery)
• User Manual (this document)

Figure 1: AEMC INSTRUMENTS Model 6255 Micro-Ohmmeter.The image displays the AEMC Model 6255 Micro-Ohmmeter housed within its robust yellow protective case, which is shown open. The device itself is yellow and black, featuring a clear LCD display that shows "72.6" and "0.1365 mΩ". To the left of the display are red and black input terminals labeled C1, P1, P2, and C2. Below the display are several control buttons. On the right side, there is a large rotary dial and a yellow START/STOP button. The overall design emphasizes durability and ease of use for industrial applications.

Key Components:

• LCD Display: Provides clear readings of resistance values, current, and other operational parameters.
• Input Terminals (C1, P1, P2, C2): For connecting test leads to the circuit under test. These are typically used for 4-wire (Kelvin) measurements to eliminate lead resistance.
• Control Buttons: Used for navigating menus, setting parameters, and initiating tests.
• Rotary Selector: For selecting measurement ranges or functions.
• START/STOP Button: Initiates and terminates resistance measurements.
• Protective Case: Durable yellow case designed to protect the instrument in various environments.

4. Setup

4.1 Initial Charging

The AEMC Model 6255 is powered by an 8.5Ah NiMH battery. Before first use, or if the battery is low, connect the provided charger to the instrument and a suitable power outlet. Allow sufficient time for the battery to fully charge. The charging indicator on the device will provide status.

4.2 Connecting Test Leads

The Model 6255 utilizes a 4-wire (Kelvin) measurement method for high accuracy, which requires four connections to the test object. This method minimizes the impact of lead resistance on the measurement.

1. Ensure the instrument is turned off before connecting leads.
2. Connect the current leads (C1 and C2) to the outer points of the resistance to be measured.
3. Connect the potential leads (P1 and P2) to the inner points of the resistance to be measured. These leads measure the voltage drop across the resistance.
4. Ensure all connections are secure and clean to prevent erroneous readings.

5. Operating Instructions

5.1 Powering On/Off

Press and hold the power button (if separate, or a specific function on the rotary dial) to turn the instrument on. Repeat the action to turn it off.

5.2 Selecting Measurement Mode

Use the rotary selector switch to choose the desired measurement range or mode. The Model 6255 supports resistance measurements from 0.1 microhm to 2500 ohms.

5.3 Performing a Measurement

1. Ensure the test leads are correctly connected to the object under test as described in Section 4.2.
2. Select the appropriate measurement range using the rotary dial. If unsure, start with a higher range and decrease as needed.
3. Press the START/STOP button to initiate the measurement. The instrument will apply a test current (0.1A to 10A) and display the resistance value on the LCD.
4. Wait for the reading to stabilize. The LCD will show the measured resistance with 0.1 microhm resolution.
5. Press the START/STOP button again to stop the measurement.

5.4 Data Storage and Recall

The Model 6255 can store up to 1500 test results. Refer to the on-screen menu or specific buttons (e.g., "MEM" or "SAVE") for instructions on saving and recalling measurements. The RS232 interface allows for data transfer to a computer for further analysis.

6. Maintenance

6.1 Cleaning

Regularly clean the instrument's casing and display with a soft, damp cloth. Do not use abrasive cleaners or solvents. Ensure the instrument is turned off and disconnected from any power source before cleaning.

6.2 Battery Care

To prolong the life of the 8.5Ah NiMH battery:

• Recharge the battery when the low battery indicator appears.
• Avoid deep discharges where possible.
• If storing the instrument for an extended period, ensure the battery is partially charged (around 50%) and recharge it every few months.
• Do not expose the battery to extreme temperatures.

6.3 Calibration

The AEMC Model 6255 is a precision instrument. While the product description states "No Calibration Certificate" is included, periodic calibration by a qualified service center is recommended to ensure continued accuracy and compliance with industry standards. Contact AEMC INSTRUMENTS for calibration services.

7. Troubleshooting

8. Specifications

9. Warranty Information

AEMC INSTRUMENTS products are designed and manufactured to the highest quality standards. For specific warranty terms and conditions applicable to your Model 6255 Micro-Ohmmeter, please refer to the warranty card included with your product or visit the official AEMC INSTRUMENTS website. Typically, warranties cover defects in materials and workmanship under normal use.

Please retain your proof of purchase for any warranty claims.

10. Customer Support

For technical assistance, service, or repair of your AEMC Model 6255 Micro-Ohmmeter, please contact AEMC INSTRUMENTS customer support.

• Website: Visit the official AEMC INSTRUMENTS website for FAQs, product documentation, and support contact information. www.aemc.com
• Contact: Refer to the website or your product packaging for phone numbers and email addresses for technical support in your region.

When contacting support, please have your instrument's model number (6255) and serial number ready.