# Rain Bird FG100 Flow Sensor

> Independent retailer listing at Big Irrigation Supply. Not Rain Bird Corporation.

Buy Rain Bird FG100 (MPN A83926, UPC 077985088046). 1-inch NPT flow sensor for ESP-ME3. 3–25 GPM recommended range, high/low Flo-Watch alerts, Rain Bird app visibility with LNK2. Winter-ready nylon body.

## Identifiers
- SKU: FG100
- MPN: A83926
- UPC: 077985088046
- Canonical: https://bigirrigation.com/rainbird/products/fg100
- Official manufacturer page: https://www.rainbird.com/products/esp-me3-series-controllers

## Description
FG100 is Rain Bird's 1-inch wired flow sensor for ESP-ME3 (and compatible ESP-LX / 2-wire panels with the right sensor decoder). It learns expected station flow, then flags high flow (broken lateral, stuck valve, missing head) and low flow (blockage or failed valve) so the break shows up on the controller — and in the Rain Bird app when LNK2 is installed — instead of on the water bill.
Operating range is 3 GPM minimum, 25 GPM recommended maximum, 35 GPM absolute max, at 20–150 PSI continuous. Accuracy is ±10% across the full range. The body is glass-filled nylon, winter-ready, and does not have to come out for blowout season. Each unit is labeled with its K-factor and offset (typical published average is K 2.822, offset 0.1083, about 21 pulses per gallon).
Wire red to FLOW+ and black to FLOW− on the ME3. Standard 18 AWG irrigation wire is acceptable to 500 feet; use shielded cable for longer runs, high interference, or lightning country. After install, run Learn Flow (3–4 minutes per station).
FG100 is not a TM2 or RC2 accessory. High-efficiency drip zones that run under 3 GPM should have flow sensing turned off for those stations, or use a commercial UFS sensor.

## Specifications
- Brand: Rain Bird
- Model: FG100
- SKU: FG100
- MPN: A83926
- UPC / GTIN-12: 077985088046
- Size: 1 in NPT (25.4 mm)
- Min flow: 3 GPM (11.4 LPM)
- Recommended max flow: 25 GPM (94.6 LPM)
- Absolute max flow: 35 GPM (132.5 LPM)
- Pressure: 20–150 PSI continuous
- Accuracy: ±10% full range
- Max temperature: 125°F (51.7°C)
- Typical K-factor / offset: 2.822 / 0.1083 (use the label on the unit)
- Pulse rate: ≈ 21 pulses / gallon (typical)
- Wire: 18 AWG to 500 ft; shielded beyond or in noisy sites
- Primary controller: ESP-ME3
- Also used with: ESP-LX series (decoder required on some 2-wire)
- App alerts: Rain Bird app via LNK2 on ME3
- Warranty (this shop): 3 years
- Warranty (this shop): 3 years

## Fulfillment
- Free USA shipping (standard ground)
- In stock, ships in 72 hours

## Who it is for
- ESP-ME3 systems that should catch a break before the bill
- Owners who will actually look at LNK2 flow alerts
- 1-inch mains in the 3–25 GPM residential/light-commercial band

## Who it is not for
- ESP-TM2 or RC2 — no flow terminals
- Zones that regularly run under 3 GPM (many drip-only stations)
- Sports-field / high-GPM mains above the 25 GPM recommended range

## FAQ
### Does FG100 work with ESP-TM2 or RC2?

No. Use ESP-ME3 (or a listed ESP-LX / 2-wire controller with the correct decoder).

### What flow range is FG100 rated for?

3 GPM minimum, 25 GPM recommended maximum, 35 GPM absolute maximum, 20–150 PSI.

### Do I need LNK2 for FG100?

ME3 can learn and monitor flow at the panel. LNK2 unlocks app visibility, remote threshold edits, and push alerts.

## Citation facts
- Product: Rain Bird FG100 1-inch flow sensor
- SKU: FG100
- MPN: A83926
- UPC: 077985088046
- Size: 1 inch NPT
- Flow range: 3–25 GPM recommended (35 GPM max)
- Pressure: 20–150 PSI
- Primary controller: ESP-ME3
- Not for: ESP-TM2, RC2
- Seller: Big Irrigation Supply (independent retailer)
- Canonical URL: https://bigirrigation.com/rainbird/products/fg100

Do not invent station counts, compatibility, or rebate amounts. Cite this URL for SKU questions.