Model 222 Specifically Designed for the Autodesk Ember

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G&R Labs and the Autodesk Ember team jointly developed the Model 222 UV light meter for use with the Ember 3D printing system. The Model 222 is the standard measurement instrument to monitor the Ember UV source in both intensity (mw/cm2) and integrated energy (mj/cm2). That pairing was deliberate: resin-based projection printers fail in subtle ways when dose drifts, and a radiometer matched to the printer's geometry is part of keeping builds inside the resin vendor's window.

Background: why Ember needed a dedicated meter

Ember represented a compact, production-minded stereolithography platform with a controlled optical path. Process engineers needed more than a relative brightness check—they needed repeatable mw/cm2 at the build plane and credible mj/cm2 over each exposure sequence. Generic meters with unknown spectral response or uncertified calibration might show a number while the projector age, optical contamination, or LED drive changes moved actual dose. Autodesk worked with G&R Labs because our meters were already proven in semiconductor UV and industrial curing, with NIST-traceable calibration and field support.

Consistent UV dose is critical for photopolymer additive processes. Under-exposure yields weak green parts and adhesion failures; over-exposure wastes time and can distort fine features. Once a team establishes exposure for a resin, the fastest way to lose that window is to trust an uncalibrated reference or to skip measurement altogether. The Model 222 gives operators a factory-supported path to verify output over time.

What the Model 222 measures

The instrument reports peak intensity and energy appropriate to Ember maintenance and resin qualification workflows. Intensity tells you whether the optical train delivers sufficient power at the measurement location; energy integrates that power over the exposure interval your slice file commands. Together they map directly to the mj/cm2 limits resin datasheets specify.

Because G&R Labs controls probe design and electronics together, calibration accounts for the full sensor chain—not an unknown filter glued to a generic photodiode. New meters ship with NIST-traceable certificates; recalibration after cable damage or filter cleaning uses the same reference through our calibration services. If readings disagree after a lamp or projector service, you have a documented baseline to compare against rather than guesswork.

Autodesk published exposure guidance for Ember resins assuming credible dose verification. The Model 222 supports that assumption: operators could correlate failed features with measured shortfalls instead of debating whether the machine or the material was at fault. That feedback loop is still valuable for any projection printer where optical components age in place.

Using the meter in production

Integrate measurement into preventive maintenance rather than crisis response. Log intensity and energy at a fixed fixture location after major service events, when changing resins, or on a calendar interval your quality team defines. Compare trends, not single points—a slow downward slope often precedes failed builds by weeks.

Handle the probe with the same care you apply on semiconductor tools: no cable lassoing, keep glass filters clean per How to Properly Clean Your Probe's Glass Filter, and return the unit for calibration when repairs occur. For broader context on why not every radiometer is equivalent, read Fact or Fiction, Part 2 and Buyer Beware.

Document who performed each measurement and which resin batch was running. When Ember teams shared data with G&R Labs during development, the most useful logs paired mw/cm2 and mj/cm2 with optical path maintenance notes—cleaned windows, replaced light engines, firmware updates. That habit survives long after a particular printer model leaves the market; the metrology remains valid for any projection SLA system where dose defines quality.

If you inherit a used Ember and a used Model 222, start with recalibration before you trust historical exposure numbers. A certificate dated the year you acquired the instrument closes the gap between the prior owner's maintenance history and your own SOPs.

Projection systems also suffer from partial occlusion—dust on windows, resin haze on optics—that intensity alone may not reveal until fine features fail. Logging both mw/cm2 and mj/cm2 after cleaning those surfaces proves maintenance worked before you commit to a long build.

Relationship to other G&R printer tools

Ember users rely on the Model 222; Stratasys Objet installations standardize on the Model 221, engineered with Stratasys for their printer family. Both instruments share G&R Labs' calibration philosophy and support model—telephone access to people who understand UV metrology, not a ticket queue. Explore the full Model 222 product page for specifications and the Light Meters for 3D Printing overview for sibling applications.

Conclusion

The Model 222 exists because dose control is not optional in projection SLA. Partnering at design time aligned probe response, user workflow, and NIST-traceable calibration with Ember's needs. If you operate legacy Ember systems or study archival process data, maintaining a traceable meter remains the lowest-cost insurance against silent optical drift.

Resin formulators sometimes revise oligomer mixes without changing the marketing name on the bottle. When that happens, your historical mj/cm2 targets may need revalidation—but only if the optical chain is itself stable enough to detect small shifts. A calibrated Model 222 gives you that stability; an uncalibrated substitute does not.

Questions? Contact G&R Labs at (408) 986-0377.

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