An open-protocol bench densitometer for industrial radiography film, paired with a native calibration application that runs inside the Avalon platform — no proprietary utility, no obsolete drivers, no serial-port roulette.
A printed structural housing, a precision plunger, a white-acrylic diffuser plate cut from a known-good DXF, and a USB-C port that talks to anything you connect.
The Avalon calibration app walks the operator through a step-wedge sweep, captures every reading directly into the platform's database, and prints a signed certificate at the end.
The Avalon densitometer speaks a simple ASCII protocol over USB-C — readable in any serial terminal, scriptable from any language, and documented in full for anyone who wants to integrate it themselves.
| Command | Description | Response |
|---|---|---|
| READ | Take a single density reading | D=2.345,T=0,STAT=OK |
| ZERO | Zero against current aperture position | OK |
| CAL?n | Read calibration coefficient n | CAL=n,VALUE=… |
| CAL=n,v | Set calibration coefficient n to v | OK |
| STEP n | Drive plunger to step n (0–127) | OK |
| STATUS | Return device status word | STAT=…,FW=…,SN=… |
| RESET | Soft-reset the controller | OK |
Because the protocol is plain ASCII, the densitometer drops in to existing QA workflows without forcing a rewrite — but the matching software is where it really earns its keep.
| Measurement type | Transmission, visible-light |
| Density range | 0.00 D to 4.50 D |
| Repeatability | ±0.02 D typical at 2.50 D |
| Aperture | 2 mm round, swappable; 1 mm option |
| Light source | Stabilized white LED, diffuser-mounted |
| Detector | Photodiode with on-board ADC, 16-bit |
| Mechanism | Stepper-controlled plunger, 200 step/mm |
| Interface | USB-C, CDC-ACM serial class |
| Protocol | ASCII, line-terminated, documented |
| Software | Avalon Calibration App, native to the platform |
| Operating temperature | 5 °C to 40 °C, non-condensing |
| Power | 5 V via USB-C, < 500 mA peak |
| Dimensions | 180 × 130 × 95 mm |
| Weight | ~ 850 g |
| Warranty | One year, parts and labor |