Elcometer 224 Digital Surface Profile Gauge

Overview

The Elcometer 224 Digital Surface Profile Gauge measures the peak-to-valley height of a blast-cleaned or abraded surface before coating is applied. Surface profile, sometimes called anchor pattern, controls how well a coating keys into the steel, so it is one of the first quality checks on any protective coating job. The Elcometer 224 reads profiles from 0 to 500 µm (0 to 20 mils) with a resolution of 1 µm and an accuracy of plus or minus 5% or 5 µm, whichever is greater, and it is available as an integral gauge or as a separate gauge with flat and convex surface probes. Elcometer states compliance with ASTM D 4417-B, SANS 5772, SSPC PA 17, US Navy NSI 009-32 and US Navy PPI 63101-000.

Seven Star LLC supplies the Elcometer 224 to blasting and painting contractors, third-party inspectors, pipe coating plants and maintenance departments across the Sultanate of Oman and the GCC. Our Muscat team helps customers choose between integral and separate versions, Model B and Model T, and flat or convex probes, and we offer engineering support in Muscat for gauges, replacement tips and calibration kits.

Measurement Principle of the Elcometer 224

The Elcometer 224 uses a direct contact method. A spring-loaded probe with a tungsten carbide tip of 60 degree angle and 50 µm tip radius sits inside a flat foot. When the foot rests on the peaks of the blasted surface, the tip drops into the valleys, and the gauge measures how far the tip travels relative to the foot. That distance is the local peak-to-valley height. As general background, this is the digital depth micrometer approach described in method B of ASTM D 4417, which complements the replica tape and comparator methods used on some projects.

Before use, the Elcometer 224 is zeroed on a glass zero tile so the foot and tip read zero on a perfectly flat surface, and it can be checked against calibration foils of nominal 125 µm and 508 µm. Elcometer describes a typical procedure: hold the probe at 90 degrees to the surface, take 5 or 10 readings within a 100 mm diameter area to form one spot measurement, display either the average or the maximum of those readings depending on the selected mode, and record five spot measurements for each 1 m by 1 m area to establish the average profile.

Engineering Design of the Elcometer 224

The Elcometer 224 shares the rugged body style of the current Elcometer digital gauges. It has a 2.4 inch (6 cm) QVGA colour TFT display at 320 by 240 pixels, automatic rotation in four orientations, an ambient light sensor and an emergency light mode. Two AA batteries give about 24 hours of continuous use at one reading per second, and the gauge can also be powered from a PC through USB. The integral gauge measures 168 by 73 by 37 mm and weighs 218 g, while the separate gauge measures 141 by 73 by 37 mm and weighs 161 g. Operating temperature is minus 10 to plus 50 °C and storage temperature is minus 10 to plus 60 °C, and the gauge is dust and waterproof to a level equivalent to IP64.

The separate version of the Elcometer 224 uses interchangeable probes. Flat surface probes come with a standard cable (T224C500US) or an armoured cable (T224C500UARM) and need 25 mm minimum sample diameter. Convex surface probes (T224C500UX and T224C500UXARM) measure on pipes down to 75 mm outside diameter, which is useful on pipe spools and small vessels where a flat foot would rock. The tungsten carbide tip is user replaceable and Elcometer rates it for up to 20,000 readings.

Key Features

The Elcometer 224 offers the following benefits to coating inspectors:

• A digital reading of profile height from 0 to 500 µm replaces subjective visual comparison with a recorded number.
• Accuracy of plus or minus 5% or 5 µm and 1 µm resolution suit typical blast profile specifications.
• Integral and separate gauges with flat and convex probes cover plates, structural steel and pipe down to 75 mm diameter.
• A reading rate of more than 50 readings per minute speeds up surveys, with up to 25 per minute on the convex probe.
• Model T stores 150,000 readings in 2,500 alphanumeric batches with date and time stamps.
• Live statistics include number of readings, mean, standard deviation, highest, lowest and coefficient of variation.
• Model T adds Bluetooth, high and low limits, fixed batch sizes, trend graphs and ElcoMaster software.
• Replaceable tungsten carbide tips and an IP64-equivalent housing suit dusty blasting environments.

Industrial Applications

Abrasive blasting is standard surface preparation for pipelines, storage tanks, pressure vessels, offshore structures and bridges, and most coating specifications state a minimum and maximum profile. Too low a profile reduces adhesion, while too high a profile can leave peaks poking through the primer. The Elcometer 224 lets the inspector confirm the profile before the first coat, store the evidence in batches and attach it to the inspection report, which supports hold points under project quality plans.

In Oman, the Elcometer 224 is relevant to blasting yards in Sohar and Muscat, pipe coating work for oil and gas flowlines, tank refurbishment at terminals and ship repair in Duqm, where readings must be repeatable for clients and inspectors. Seven Star LLC supplies the Elcometer 224 alongside related equipment such as the Yowexa EC-900 coating thickness gauge for the following DFT checks, the Dakota NDT CMX3-DL corrosion thickness gauge and the Waygate DM5E ultrasonic thickness gauge for steel wall surveys.

Model Options and Accessories

Elcometer lists the Elcometer 224 as Model B or Model T in integral or separate form: E224C-BI and E224C-TI for the integral gauges, and E224C-BS and E224C-TS for the separate gauges, with separate probes ordered on their own. Model B gives fast readings, statistics and USB output with a five-reading memory. Model T adds full memory, Bluetooth to computers and mobile devices, user limits, batch types including counted average, and review graphs. Accessories include a probe tip protection cap (T22419793), a glass zero tile with wallet (T22420072), a certified calibration test kit with 125 µm and 500 µm foils (T22421882C), replacement tips in packs of 2 or 5, a USB cable and a benchtop inspection stand for the separate gauge.

Technical Specifications

The table below summarises the Elcometer 224 data published in the Elcometer datasheet:

How to Order

To order the Elcometer 224, tell Seven Star LLC whether you need an integral or separate gauge, Model B or Model T, and whether you will measure flat steel or pipe, and our instrumentation team in Muscat will send a formal quotation. The Elcometer datasheet can be downloaded from this page, and we provide engineering support in Muscat for Elcometer 224 gauges, probes, tips and calibration kits for customers in Oman and the GCC.