Starrett 749.1 - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features

The Starrett 749.1 Electronic Depth Micrometer is a precision measuring instrument designed for accurate depth measurements. This user-friendly device combines advanced electronic features with robust construction, making it suitable for a wide range of industrial and workshop applications.

Function Description

The 749.1 Depth Micrometer provides precise depth measurements with a resolution of 0.00005" and 0.001mm. It features an electronic display that shows measurements in both English (inches) and Metric (millimeters) units, which can be toggled via the IN/mm button. The device includes a "Preset" function to set a specific starting value, a "Zero" function to set the display to zero at any point, and an "ABS" (Absolute) mode to return to the true zero from the base of the measuring rod.

The micrometer is equipped with a "Limits" function, allowing users to set upper and lower tolerance limits for measurements. When a measurement falls outside these limits, the display will flash, indicating an out-of-tolerance condition. The "Hold" function freezes the current reading on the display, which is useful for recording measurements in difficult-to-view positions.

The device operates with a removable measuring rod, and different rod lengths are available to accommodate various depth ranges. The measuring rod can be easily changed and adjusted for proper seating and calibration. The thimble, which is the rotating part used to advance or retract the measuring rod, is graduated to 25 thousandths (0.025") per revolution, with every fourth line designating a hundred thousandths. The sleeve is marked with lines representing 0.100", 0.050", and 0.025" increments, facilitating easy reading of the main measurement.

Data output is a key feature, with the 749.1 micrometer supporting various data transmission methods. It can connect to a PC via a USB port using Starrett DataSure® Advanced 4.0 Wireless Data Collection System or through traditional wired connections (795.1 Smart Cables). This allows for efficient data collection, analysis, and documentation.

Important Technical Specifications

Resolution: 0.00005" and 0.001mm
Accuracy (in): Mic head +/-.0001"; Rods +/-.0002"
Accuracy (mm): Mic head +/-.003mm; Rods +/-.005mm
Rod Range: 0-12"/0-300mm
RS232 Output: 4800 BAUD, 8 data bits, no parity, 1 stop bit, and ASCII data
Base Length: 4"
Rod Diameter: 5/32"
Battery: CR2032 3 volt lithium coin-cell
EMC Directives, CE Mark: These micrometers conform to the following 89/336/EEC EMC Directive, Standards: EN50011: Radiated and conducted Emissions Requirements EN61000-6-2 – Generic Heavy Industrial

The micrometer is powered by a CR2032 lithium coin-cell battery, which is easily replaceable. The battery status is indicated by an icon on the display.

Usage Features

The 749.1 Depth Micrometer is designed for ease of use. To begin measuring, the user simply turns the thimble to move the spindle to zero. The "SHIFT/SET" button is used in conjunction with other buttons to access secondary functions, indicated by yellow text on the buttons.

Setting Preset: The "PRESET" button allows the user to input a specific starting value. This is particularly useful when measuring from a non-zero reference point or when using gauge blocks.
Setting Limits: The "LIMITS" button enables the user to set minimum and maximum tolerance values. The display will show "MIN LIMIT" and "MAX LIMIT" icons, and the measurement will flash if it falls outside these boundaries.
Changing Measuring Rods: The device accommodates various measuring rod lengths. To change a rod, the user unscrews the ratchet thimble, pulls out the old rod, inserts the new rod, and then screws the ratchet thimble back on. It is crucial to ensure the rod is properly seated and adjusted for accuracy. A simple check involves measuring a gauge block or surface plate to confirm the zero point.
Adjusting the Measuring Rod Nut: If the measuring rod needs adjustment for proper seating or to eliminate play, a spanner wrench can be used to turn the rod nut. This ensures that the rod is firmly seated and provides accurate measurements.
Data Output: The micrometer supports multiple data output options, including Starrett DataSure® wireless systems and wired USB connections. This allows for seamless integration into data collection systems, enhancing efficiency and reducing manual transcription errors.

Maintenance Features

Proper maintenance ensures the longevity and accuracy of the 749.1 Depth Micrometer.

Cleaning: The device should be kept clean and free from debris. Avoid dropping the Depth Micrometer, as shocks can affect its accuracy.
Lubrication: Do not apply any type of lubricant to the Rod or other parts, as this can attract dirt and affect performance.
Battery Replacement: The micrometer uses a CR2032 lithium coin-cell battery. To replace the battery, the battery cover is removed, the old battery is taken out, and a new one is inserted with the positive side down. The battery icon on the display indicates the battery status.
Calibration: Regular calibration is essential to maintain accuracy. The micrometer can be calibrated by moving the thimble slowly until numbers are displayed, then moving it to "Cal" mode, and pressing the thimble or quickly pressing a button. This process ensures that the device provides reliable measurements over time.
Storage: When not in use, the micrometer should be stored in a clean, dry environment, away from direct sunlight or extreme temperatures. Avoid storing it in areas with high humidity or where it might be exposed to corrosive substances.

The Starrett 749.1 Electronic Depth Micrometer is a versatile and reliable tool, offering high precision, user-friendly operation, and robust data management capabilities, making it an invaluable asset for quality control and precision measurement tasks.