# Testo 510i + 405i → Velocity Report App

You have two useful Smart Probes for duct work:

| Probe | Measures | Use in Field app |
|-------|----------|------------------|
| **testo 510i** | Differential / velocity pressure (ΔP) with pitot | Unit: **VP / ΔP (in. w.g.)** |
| **testo 405i** | Air velocity + temperature (thermal anemometer) | Unit: **Velocity (FPM)** |

Both pair with the **testo Smart App**. The Field app does **not** replace Smart App for live display — you read the probe there (or Capture numbers into this report).

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## Which probe for a velocity traverse?

### Option A — Pitot traverse (classic VP method) → **510i**
- Use 510i + pitot tube / hoses.
- App unit: **VP / ΔP (in. w.g.)**.
- Report calculates FPM from VP using baro/temp (density).
- Matches the original Excel velocity-pressure worksheet.

### Option B — Direct velocity traverse → **405i**
- Insert 405i probe into duct at each traverse point.
- App unit: **Velocity (FPM)** (set Smart App to fpm / ft/min if available).
- Field app converts FPM → equivalent VP for the grid using baro/temp, then runs the same report math.
- Also enter **temperature** from the 405i into the Field app Temp (°F) field when practical.

You can mix jobs (some sites pitot, some hot-wire) — just switch the unit radio before capturing.

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## Field workflow (both probes)

1. Install **testo Smart App** and connect **510i** and/or **405i**.
2. Open Field app → **Add to Home Screen** (recommended).
3. Fill project info + duct size + baro + design flow.
4. Pick the matching unit:
   - 510i → **VP / ΔP**
   - 405i → **Velocity (FPM)**
5. At each point: read Smart App → type value → **Capture → next cell**.
6. Or export/log from Smart App → **Import from Smart App**.

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## 510i specifics
- No onboard screen — Smart App is the display.
- Units: **inH₂O / in. w.g.** for pitot VP.
- Zero / hose setup as Smart App instructs before traverse.
- Part number often **0560 1510**.

## 405i specifics
- Telescopic hot-wire probe; measures **velocity** (and temperature).
- Units: **fpm** (or m/s — convert: fpm = m/s × 196.85).
- Keep probe parallel to flow; follow Testo orientation tips.
- Part number often **0560 1410**.
- In Field app, **FPM mode is required** so values convert into the VP grid correctly.

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## Bluetooth button

Same as before: **Chrome on Android** only; 510i/405i usually stay locked to Testo Smart App for live values. Prefer **Capture** or **Import**.

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## Quick chooser

| Job | Probe | Unit in Field app |
|-----|-------|-------------------|
| Pitot VP traverse | 510i | VP / ΔP |
| Hot-wire velocity traverse | 405i | Velocity (FPM) |
| Need air temp for density | 405i (temp) → enter in Temp (°F) | — |
| Logged multi-point table | Either → CSV/paste import | Match probe type |

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## Install Field app

Portal → **Open Velocity Report App** → browser **Add to Home Screen**.  
See also `SHAREABLE-LINK.md` for hosting a shareable link.