While all six models share the same foundational X-ray fluorescence (XRF) technology and are evaluated using Fischer’s WinFTM® software, they are engineered for distinctly different tier levels of precision, sample handling, and target applications.

1. Electronic Components (Detectors & Processors)

The core electronic components dictate how well the machine can separate adjacent elements on the periodic table (e.g., distinguishing gold from platinum or identifying trace elements).

  • GOLDSCOPE SD 520 & 550: These are optimized specifically for the precious metals industry. Both utilize a Silicon Drift Detector (SDD) with a resolution of ≤ 140 eV. The latest iterations feature Fischer’s Digital Pulse Processor (DPP+), which processes pulses significantly faster. They are available with standard 20 mm² detectors or upgraded 50 mm² detectors for ultra-high count rates.
  • XAN 220 & 222: These are standard performance models. They utilize a standard Silicon Drift Detector (SDD) with a slightly lower resolution ceiling of ≤ 160 eV.
  • XAN 250 & 252: These are high-performance models designed for thin functional coatings (like in electronics) and trace analysis (RoHS). They also use the SDD (≤ 160 eV resolution) but are paired with more advanced high-voltage tubes (switching between 10 kV, 30 kV, and 50 kV) compared to the XAN 220/222 which switch between 30, 40, and 50 kV.

2. Features: Filters and Apertures (Collimators)

Filters and apertures condition the X-ray beam to optimize the excitation of specific elements while blocking out background noise.

  • GOLDSCOPE SD 550, XAN 250, & XAN 252 (The Most Versatile): These three models feature highly flexible, motorized beam conditioning. They include 4x changeable apertures (Ø 0.2, 0.6, 1.0, and 2.0 mm) and 6x changeable primary filters (Nickel, Aluminum 1000 µm, Al 500 µm, Al 100 µm, Mylar® 100 µm, and a “free” slot).
  • GOLDSCOPE SD 520: This model sits in the middle. It features the 4x changeable apertures (0.2 to 2.0 mm), but standard configurations often feature a fixed Aluminum filter (or fewer changeable options) compared to the 550, streamlining it for dedicated gold/alloy testing rather than complex trace analysis.
  • XAN 220 & XAN 222 (The Most Basic): These models feature a fixed aperture (Standard Ø 1.0 mm, with optional 2.0 mm or 0.6 mm chosen at purchase) and lack the 6-way changeable filter carousel. This limits their ability to instantly adapt to highly complex, multi-layer trace analysis compared to the 250/252 series.

3. Operable XY Stage and Accuracy

None of these specific six models feature the fully automated, programmable, motor-driven XY-stages (with ≤ 0.005 mm repeatability) found in Fischer’s ultra-premium XDV-SDD line. Instead, the differences lie in manual sample placement.

  • Fixed Stages (GOLDSCOPE 520, GOLDSCOPE 550, XAN 220, XAN 250): These feature a flat, fixed sample support base. The user places the jewelry or part over the measurement window manually. The “accuracy” of placement relies entirely on the operator using the digital crosshairs and video microscope.
  • Manual XY Stages (XAN 222, XAN 252): The “2” at the end of these model numbers designates an upgraded chassis. They feature a manually operable XY stage and a larger measuring chamber (accommodating parts up to 174 mm high, versus 90 mm on the fixed models). The accuracy is based on the operator turning precision micrometers to align small parts (like electronic pins or tiny watch components) under the crosshairs.

4. Long-Term Stability

  • All Models: A hallmark of the FISCHERSCOPE and GOLDSCOPE series is their distance compensation (patented DCM method) and thermal stability. The data sheets state that the necessity of recalibration is drastically reduced.
  • Repeatability: For gold measurements (60-second test time), all of these models achieve a repeatability precision of ≤ 0.5 ‰ (per mil), which is the standard required for official hallmarking and high-end refining.

5. Speed and Performance

  • GOLDSCOPE SD 520 & 550 (Fastest for Precious Metals): Thanks to the integration of the DPP+ processor, these models can achieve up to a 45% reduction in absolute standard deviation at the same measuring time as older models. Alternatively, they can reduce the measurement time by a factor of 3 while maintaining the same precision.
  • XAN 250/252 (Best for Thin Coatings): While perhaps slightly slower in raw pulse processing than the DPP+ Goldscopes, their performance excels in detecting light elements (down to Aluminum) and extremely thin functional coatings (nanometer scale) due to their flexible 10kV tube settings and multi-filter setups.
  • XAN 220/222 (Standard Performance): Highly accurate but optimized for standard bulk alloy analysis and thicker gold/silver coatings rather than nanometer-level electronics analysis.

Electronic Components (Inside the XAN 250 Unit)

The XAN 250 is defined by its core hardware tier, so the fundamental specs (the Micro-focus tungsten tube and the 10/30/50 kV high-voltage steps) have not changed. However, the internal processing boards have.

  • 2018 Detector Processing: Used a standard Silicon Drift Detector (SDD) with a resolution of ≤ 160 eV. The internal pulse processor sent data to the PC at a standard rate.
  • 2026 Detector Processing: While it uses the same class of SDD (≤ 160 eV), Fischer continually updates the internal Digital Pulse Processors (DPP). Modern internal electronics handle significantly higher “count rates” (the number of X-ray photons the detector can process per second).
  • The Result: Even though it’s the “same” machine, a 2026 unit will experience less “dead time” (the fraction of a second the detector goes blind to process a hit) and will reach the same level of statistical precision faster than a 2018 unit.

Summary of the Upgrade

If you were to upgrade from a 2018 XAN 250 to a 2026 XAN 250, you would not necessarily be getting “deeper” X-ray penetration. Instead, you are paying for speed, workflow automation, and mistake-proofing. The 2026 PC and software eliminate operator error through auto-recognition and make navigating complex trace analysis drastically faster.