Decision 1: Vertical or Horizontal?
The axis of the light path decides how the part sits. That depends on the shape of your parts.
| Vertical | Horizontal | |
|---|---|---|
| How the part sits | Flat on a glass stage, light passing through from below | Held between centres, on a V-block or in a fixture, light passing horizontally |
| Best for | Stampings, gaskets, flat moulded parts, small turned parts, PCB features | Shafts, threads, long and heavy turned parts, parts that are awkward to stand on end |
| Limitations | Long cylindrical parts must stand upright or need fixtures | Flat, thin parts are harder to hold |
| Optomech range | PP 300TL, 300TLE, 300TE, 400TE, 600VE | PP 400H, PP 600H |
Decision 2: Screen Size and Field of View
The useful formula is field of view ≈ screen diameter ÷ magnification.
| Screen | At 10× | At 20× | At 50× |
|---|---|---|---|
| Ø300 mm | ≈ 30 mm | ≈ 15 mm | ≈ 6 mm |
| Ø400 mm | ≈ 40 mm | ≈ 20 mm | ≈ 8 mm |
| Ø600 mm | ≈ 60 mm | ≈ 30 mm | ≈ 12 mm |
If your largest critical feature fits on screen at the magnification you need, you can compare it in one view. If not, measure across it by moving the stage with encoders and a DRO. A bigger screen also makes overlay-chart work easier on complex profiles, and reduces operator fatigue on long shifts.
Decision 3: Stage Travel, Part Size and Load
Check three numbers against your largest part: traverse (how far the stage moves in X and Y), maximum part diameter and load capacity. Travel limits the longest distance you can measure with the encoders. Part diameter and load limit what physically fits. Allow for fixtures, which add weight and height.
Decision 4: Magnification and Illumination
- Lenses. 10× is the common general-purpose lens. Higher magnifications (20×, 50×, 100×) resolve fine features such as small radii and thread roots, but shrink the field of view. On Optomech's encoder models, 5×–100× lenses are interchangeable across the PP 300TLE to PP 600VE.
- Profile (transmitted) light shows the silhouette of the part, which is what most profile measurement uses.
- Surface (reflected) light shows features on the face of the part, such as markings, steps and blind features. Check its quality if you need surface work.
Decision 5: Readout and Reporting
| Option | What you get | Suits |
|---|---|---|
| Micrometer stage, no DRO (PP 300TL) | Micrometer heads (10 µm) and manual screen rotation | Overlay-chart, go/no-go and incoming checks |
| OP-250 | Simple digital readout of the axes | Basic dimension recording |
| OP-500 | Edge detection and geometric functions | Faster, less operator-dependent measurement |
| OP-1000 | PC-based measurement with DXF and SPC | Reports, drawing comparison, SPC programmes |
If customers ask for dimensional reports or SPC data, the readout matters more than the screen size. See SPC and Cpk with optical metrology.
How to Read the Accuracy Specification
Profile projector brochures usually quote contour (profile) accuracy and surface accuracy as a percentage, for example ±0.05% on Optomech encoder models and ±0.1% contour on the PP 300TL. This is magnification accuracy: how closely the projected image matches the stated magnification. As a rough illustration, ±0.05% on a 10 mm feature compared on screen corresponds to about ±5 µm from magnification alone. Total measurement uncertainty also includes edge judgement by the operator, focus, temperature and, for stage measurements, the encoder and stage. Read measurement uncertainty explained, and ask for NABL-traceable calibration. See NABL traceability.
Model Selector
Specifications as published on the Optomech product pages. Confirm the configuration for your application.
| Model | Type | Screen | Traverse (X × Y) | Max part / load | Accuracy (contour) | Readout |
|---|---|---|---|---|---|---|
| PP 300TL | Vertical | Ø300 mm | 25×25 or 50×50 mm | Ø60 mm / 5 kg | ±0.1% | Micrometer (no DRO) |
| PP 300TLE | Vertical | Ø300 mm | 100×100 mm | Ø60 mm / 10 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
| PP 300TE | Vertical | Ø300 mm | 200×100 mm | Ø130 mm / 25 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
| PP 400TE | Vertical | Ø400 mm | 250×150 mm | Ø170 mm / 25 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
| PP 600VE | Vertical | Ø600 mm | 250×150 mm | Ø210 mm / 25 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
| PP 400H | Horizontal | Ø400 mm | 250×150 mm (motorised) | Ø170 mm / 25 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
| PP 600H | Horizontal | Ø600 mm | 300×600 mm | Ø210 mm / 25 kg | ±0.05% | 1 µm encoders; OP-250/500/1000 |
Quick rules: choose the PP 300TLE to move up from micrometer-only inspection to encoder measurement on small parts; choose the PP 400TE (our most popular vertical model) for typical automotive and precision-engineering parts; choose the PP 600VE when complex profiles need maximum screen area; and choose a horizontal model for shafts and long turned parts.
Questions to Ask Before You Order
- Which lenses are included, and what do extra lenses cost?
- Which readout tier is quoted, and can it be upgraded later?
- Is calibration NABL-traceable, and what does the certificate cover?
- Are overlay charts, fixtures, centres or V-blocks included for your parts?
- What installation, training and service support is provided, and where are spares held?
For Optomech starting-from price bands, see the profile projector price guide for India. If you are weighing up automation, compare profile projector vs VMM.