# 📐 L2 Spec — UV-Vis Concentration Spec
**ID:** `L2-145-001` · **Status:** ⊙ Testnet (genesis catalog)
**Parents:** ⬆ Principle [`L1-145`](/artifact/l1/L1-145)
> **🎯 Tolerance (ε):** expression
> **⚖ Difficulty score:** 0.35 · **Delta tier:** 5
> **⛓ On-chain block:** 41554231
---
## 1. Domain Ω
**Type:** `range`
| Parameter | Unit | Range |
|---|---|---|
| K | — | 1 – 20 |
| N lambda | — | 50 – 5000 |
| Stray light | — | 0.0 – 0.01 |
| Baseline drift | — | 0.0 – 0.1 |
| Path length cm | — | 0.01 – 10 |
| Scatter turbidity | — | 0.0 – 1.0 |
| Pure component uncertainty | — | 0.0 – 0.2 |
## 2. Tolerance (ε)
**Type:** `fn`
```
5e-5 + 0.01 * stray_light / 1e-3 + 1e-3 * scatter_turbidity + 5e-4 * pure_component_uncertainty
```
## 3. Difficulty
| Property | Value |
|---|---|
| Difficulty score | 0.35 |
| Delta tier | 5 |
## 4. Fingerprint
`a55a0be367e4c0a12ae7bf989a8915658b1343a0017b03954427bb364ae3d10f`
## 5. On-chain Registration
- **Chain hash:** `0x0483090da38d8c6e5fa63eee5def06771f8ea6d04c6bd6a732c0b3d3339875fe`
- **Chain tx hash:** `0x9b978099fc8c2d9c4375640450f42d961ffe6adb1e7347cec251e36423c722ce`
- **Chain block:** `41554231`
---
## File Mapping
This bundle consists of: `L2-145-001.md`, `L2-145-001.json`.
| File | Role | How to regenerate |
|------|------|-------------------|
| `L2-145-001.md` | Source of truth — edit this | Human or LLM |
| `L2-145-001.json` | Structured metadata for the registry | LLM regenerates from the sections above |
**Prompt for your LLM after editing this Markdown:**
> Read the attached Markdown. Regenerate the sibling `.json` so every field matches.
> Preserve the schema documented in the rows above.
> Output each file in its own fenced code block tagged with the filename.
> Output only the JSON object.
_This Markdown was auto-synthesized from the catalog row for `L2-145-001`._
_Edit it, regenerate the JSON, and submit at [/submit](/submit) to claim the artifact._