How to Measure Surface Profile 4:35
In this video, learn how to use DeFelsko’s PosiTector SPG series of Surface Profile Gauges. They use a digital depth micrometer fitted with a fine pointed probe.
The PosiTector SPG is a digital depth micrometer designed to accurately record the peak-to-valley heights (surface profile) of blasted steel, textured coatings, concrete, or other substrates.
These measurements ensure that the surface is properly prepared before applying protective coatings, helping avoid adhesion failure, uneven coating, or premature corrosion.
With fast measurement rates, durable probe tips, and full traceability, the DeFelsko PosiTector SPG from DFT Instruments offers a robust solution for field or workshop use.
Each unit is supplied calibrated, with a 2 year warranty, and backed by UK-based service and support.
Features
-
Accurate Surface Profiling – Measures and records peak-to-valley roughness to verify surface preparation and coating specifications.
-
Standards Compliance – Meets or exceeds ASTM D4417-B, AS 3894.5-C (with optional 30° tip), U.S. Navy NSI 009-32, SANS 5772, and related international standards.
-
Larger Impact-Resistant Display – 2.8-inch colour touchscreen with an updated keypad for smooth, intuitive menu navigation.
-
Rugged & Weatherproof – IP65-rated housing is resistant to dust, water and job-site abuse.
-
Long-Life Probe Tip – Alumina wear face and tungsten-carbide tip ensure continuous accuracy; the tip is field-replaceable for convenience.
-
Interchangeable Platform – Compatible with the full PosiTector probe family, allowing one gauge body to serve multiple measurement needs.
-
Rapid Data Collection – Captures 50+ readings per minute, ideal for large surface areas and production environments.
-
Versatile Connectivity – Built-in USB, Wi-Fi and Bluetooth links seamlessly with PosiSoft software for PC, Mac, or mobile devices.
-
Certified Accuracy – Supplied with a long-form Certificate of Calibration traceable to PTB for reliable, audit-ready documentation.
Why Measuring Matters
-
Ensures Adhesion & Coating Longevity
If the profile (height difference between peaks and valleys) is too low, coatings may not anchor properly, increasing risk of peeling or flaking. If too high, peaks may get under-coated, leaving them vulnerable to rust. -
Optimises Coating Usage
Knowing profile height helps to ensure the proper thickness of paint or protective coating. If you know the surface anchors well, you avoid over-application (“hiding” the profile) which wastes material and increases cost. -
Improves Quality & Compliance
Many specifications and industry standards require certain profile heights (e.g. ASTM D4417, SSPC PA 17, Navy NSI 009-32, etc.). Using the SPG gives you readings that meet or exceed those standards, helping in audits, contract verifications and quality assurance. -
Adapts Across Substrates
Whether blasting steel, preparing concrete, or evaluating textured coatings, different SPG probe styles cover a wide range of measurement ranges and environments, giving flexibility in harsh or varied site conditions.
Why Choose DFT?
-
UK-Based Calibration & Traceability
Every SPG comes with a long-form calibration certificate traceable to PTB/NIST or equivalent, ensuring your readings are valid for audits and compliance. -
Fast Local Service
Our authorised DeFelsko service centre in the UK allows for quicker repairs or probe replacements, minimising downtime. -
Genuine Instruments & Accessories
We supply authentic SPG instruments and spares (tips, probes, zero plates, etc.), assuring performance and durability. -
Hands-On Support
From selecting the best probe style (integral, cabled, textured, concrete etc.) to advice on measuring techniques and surface prep, our technical team helps ensure you get the best results out in the field. -
Proven Field Ruggedness
SPG units are designed for real-world conditions — rough surfaces, dust, moisture, and variable weather — with protective housings, wear-resistant tips, and durable design built in.
Helpful PosiTector SPG Videos
How to Create Inspection Reports 4:05
This video highlights the benefits of the PosiTector SmartLink when paired with a PosiTector SPG or any of the other compatible PosiTector gauges by DeFelsko.
Features & Benefits
-
Large 2.8-inch impact-resistant colour touchscreen with redesigned keypad for quick menu navigation.
-
Measurement rate of over 50 readings per minute—perfect for covering large areas with speed and consistency
-
Durable alumina wear face and tungsten carbide tip for long life; tips are field-replaceable.
-
IP65-rated enclosure: weatherproof, dustproof and water-resistant—suitable for job site conditions.
-
Built-in temperature compensation to maintain accuracy under changing environmental conditions.
-
Multiple probe styles: integral, cabled, OS (convex surface), CS (textured coatings), TS (concrete surfaces) options, allowing adaptation to different substrates.
-
Optional 30° angled tip for applications needing compliance with certain standards (e.g. AS/NZS, etc.).
-
Auto-rotating display with flip lock; selectable units (microns / mils); multilingual interface.
-
Data modes: statistics (avg, standard deviation, min, max, count), screen capture, Hi-Lo alarms for limit breaches.
-
Long battery life: runs off 3 AAA batteries; protective accessories included (zero plate, shim, rubber holster etc.).
Technical Specifications
| Specification | Detail |
|---|---|
| Accuracy | ±(5 µm + 5%) or ±(0.2 mils + 5%) for standard probes; more for high-range ones. |
| Tip Angle & Tip Radius | Standard 60° angle tip with ~50 µm (2 mil) radius; optional 30° tip available. |
| Size (Body without probe) | ~127 × 66 × 25.4 mm (5″ × 2.6″ × 1″) |
| Weight (Body only) | ~137 g (4.9 oz) without batteries or probe |
| Units | Microns & Mils, switchable on display |
| Display | Colour touchscreen; large size; redesigned keypad; auto-rotate & flip lock |
| Environmental Protection | IP65 rated enclosure |
| Accessories Included | Glass zero plate, metal shim, protective rubber holster, wrist strap, 3 × AAA batteries, USB cable, protective case, long-form calibration certificate, lens shield. |
Model / Probe Options Comparison Table:
| Model / Probe Type | Best For / Application | Range |
|---|---|---|
| SPG / SPG Integral | Flat steel surfaces where hand-held probe makes sense | 0-500 µm / 0-20 mils |
| SPG-OS (Outside Diameter) | Convex/curved steel surfaces (pipes, tanks) | 0-500 µm / 0-20 mils |
| SPG-CS (Textured Coatings) | Very heavy or rough coatings where deeper profile is needed | ~0-1500 µm / 0-60 mils |
| SPG-TS (Concrete Surface Profile) | Concrete or mortar substrates / overlays | ~0-6 mm / 0-250 mils |
PosiTector SPG FAQ’s
Can the SPG be used on curved surfaces or pipes?
Yes — use the SPG-OS probe (Outside Diameter mode). It has a V-groove and supports convex surfaces down to approx. 3 mm outside diameter. With the proper probe and set-up, reliable readings on curved steel are achievable.
How often should the SPG be zeroed or checked?
It’s wise to use the included glass zero plate regularly—before critical measurement sessions or after changing the probe tip. If readings vary by more than around ±5 µm (0.2 mils), perform a zero adjustment.
What is the difference between standard and advanced models?
Advanced models offer much larger storage capacity, support for many batches/subbatches, enhanced reporting, screen capture, and often better connectivity (USB, BLE, WiFi). Standard is well-suited for routine tasks.
Do the probe tips wear out, and can they be replaced?
Yes. The tips are made from tungsten carbide (and alumina wear face) which resists wear, but after extensive use tips may degrade. They are field-replaceable, and replacement tips are provided so you can maintain accuracy.
Which standards does the SPG conform to?
It meets a wide set of standards including ASTM D4417-B, SSPC PA-17, U.S. Navy NSI 009-32, SANS 5772, AS 3894.5-C (with optional 30° tip), among others.
What if I need to measure deeper or on very rough surfaces?
Use the SPG-CS probe for very rough coatings (up to ~1,500 µm), or the SPG-TS for concrete surfaces (up to ~6 mm). These options extend the measurement range to suit tougher jobs.
Still need help?
If you experience an issue, check our troubleshooting guide or contact our support team directly. As a DeFelsko Authorised Service Centre (DASC), DFT Instruments provides calibration, repair, and technical assistance locally in the UK.
Find out more about the PosiTector SPG and all the features that come with it
What’s Included:
-
PosiTector SPG gauge body (Standard or Advanced)
-
Selected SPG probe (integral or cabled type depending on model)
-
Glass zero plate & metal shim for verification
-
Protective rubber holster & lens shield
-
Wrist strap, USB cable
-
3 × AAA batteries (included)
-
Protective carrying case
-
Long-form Certificate of Calibration traceable to PTB/NIST
-
2 year warranty on body and probe
Need precise, reliable surface profile measurements? The PosiTector SPG gives you everything you need for peak-to-valley measurement with speed, durability, and audit-grade accuracy.
📞 To enquire about this product, contact our team today on: 01442 879494 or Complete the form.
PosiTector SPG Price:
PRICES FROM £360