Instruction Manual

1. Introduction

The ESI 687 DC/AC Low Current Probe/DMM is a versatile tool designed for precise current measurement in various applications. With its capability to measure down to 1 milliampere, it is particularly useful for diagnosing low current applications such as parasitic drains in automotive systems. This device combines the functionality of a current probe with a digital multimeter, offering 35 test ranges and 10 test functions, including continuity beep. Its robust design includes overload protection, auto power off, and data hold features, making it an essential instrument for professionals and enthusiasts alike.

2. Safety Information

WARNING: Always read and understand all safety instructions before operating this device. Failure to follow these instructions may result in electric shock, fire, or serious injury.

• Do not exceed the maximum input ratings for any function.
• Ensure the device is in good working condition before use. Inspect test leads for damage.
• Do not use the device in wet environments or if your hands are wet.
• Always disconnect power to the circuit before connecting or disconnecting the current probe.
• Use caution when working with live circuits.
• Replace batteries promptly when the low battery indicator appears to ensure accurate readings.

3. What's in the Box

• ELECTRONIC SPECIALTIES - Low Current Probe (687)
• Test Leads (Red and Black)
• Carrying Case
• 9-Volt Battery
• Instruction Manual (this document)

Figure 3.1: ESI 687 Low Current Probe/DMM with included test leads and batteries.

Figure 3.2: Top view of the protective carrying case for the ESI 687.

Figure 3.3: Bottom view of the carrying case, showing the integrated strap for secure transport.

4. Setup

4.1 Battery Installation

1. Locate the battery compartment on the rear of the ESI 687 unit.
2. Use a screwdriver to open the battery compartment cover.
3. Insert the included 9-volt battery, observing the correct polarity (+/-).
4. Replace the battery compartment cover and secure it with the screw.

4.2 Connecting Test Leads

For DMM functions (Voltage, Resistance, Continuity), connect the red test lead to the VΩHz% input jack and the black test lead to the COM (common) input jack.

5. Operating Instructions

5.1 Powering On/Off

Rotate the rotary switch from the "OFF" position to any desired function to power on the device. To power off, rotate the switch back to the "OFF" position. The device features auto power off to conserve battery life.

5.2 Current Measurement (AC/DC Amps)

The ESI 687 is designed for non-contact current measurement using its clamp jaw. This is ideal for measuring current through a single wire without breaking the circuit.

1. Rotate the rotary switch to the desired current range (e.g., 80A~, 4A~, 80A=, 4A=).
2. Important: Before clamping, press the "ZERO" button to zero out the meter. This compensates for any residual magnetic fields and ensures accurate readings. Perform this step in the location where you intend to measure.
3. Open the clamp jaw and encircle only one conductor (wire) of the circuit you wish to measure. Ensure the jaw is fully closed.
4. Read the current value displayed on the LCD screen.
5. The clamp opening is 5/8 inches, large enough to fit over most negative battery cables.

5.3 DMM Functions (Voltage, Resistance, Frequency, Continuity)

For other measurements, connect the test leads as described in Section 4.2.

• Voltage (VDC/VAC): Rotate the switch to the VDC or VAC position. Connect test leads across the component or circuit to measure voltage.
• Resistance (Ω): Rotate the switch to the Ω position. Ensure the circuit is de-energized. Connect test leads across the component to measure resistance.
• Continuity (Continuity Beep): Rotate the switch to the continuity position. If the circuit has continuity, the device will emit an audible beep.
• Frequency (Hz%): Rotate the switch to the Hz% position. Connect test leads to the signal source to measure frequency.

5.4 Data Hold

Press the "HOLD" button to freeze the current reading on the display. Press it again to release the hold function.

6. Maintenance

6.1 Cleaning

Wipe the device with a dry, clean cloth. Do not use abrasive cleaners or solvents. Ensure the device is powered off before cleaning.

6.2 Battery Replacement

When the low battery indicator appears on the display, replace the 9-volt battery as described in Section 4.1. Prompt battery replacement ensures continued accuracy and proper operation.

6.3 Storage

Store the ESI 687 in its protective carrying case in a cool, dry place away from direct sunlight and extreme temperatures. If storing for extended periods, remove the battery to prevent leakage.

7. Troubleshooting

8. Specifications

9. Warranty and Support

For warranty information and technical support, please contact ELECTRONIC SPECIALTIES directly. Refer to the product packaging or the official ES website for the most current contact details. Keep your purchase receipt as proof of purchase for warranty claims.

Visit the ES Store: ES Store on Amazon