# AGRINOVO-ORP-100: Digital ORP Sensor

Agrinovo technical datasheet, revision 1.2 (October 2026).
PDF version: https://agrinovo.io/datasheets/sensors/AGRINOVO-ORP-100_Datasheet.pdf

## 1. Overview

The AGRINOVO-ORP-100 is a digital Oxidation-Reduction Potential (ORP) sensor for continuous water quality monitoring. It provides high-accuracy ORP measurements through RS485 Modbus-RTU interface with single-point calibration capability.

### Key Features

- ORP range: -1999 to +1999 mV
- Resolution: 1 mV
- Accuracy: ±3 mV
- Stability: ≤2 mV/24h
- IP68 waterproof
- RS485 Modbus-RTU
- Low power: ≤0.5W
- 12-24 VDC supply

### Applications

- Agricultural irrigation
- Hydroponics and greenhouses
- Water quality testing
- Aquaculture
- Wastewater treatment
- Chemical and pharmaceutical processing

## 2. Specifications

| Parameter | Specification |
|:----------|:--------------|
| **Measurement Range** | -1999 to +1999 mV |
| **Resolution** | 1 mV |
| **Accuracy** | ±3 mV |
| **Stability** | ≤2 mV / 24 hours |
| **Power Consumption** | ≤0.5W |
| **Supply Voltage** | 12-24 VDC |
| **Operating Temp** | 0 to 60°C |
| **Operating Humidity** | ≤85% RH |
| **Protection** | IP68 |
| **Dimensions** | Ø28 mm × 160 mm |
| **Mounting Thread** | 3/4 inch NPT, front and rear |

## 3. Wiring

| Wire Color | Function | Description |
|:-----------|:---------|:------------|
| **Red** | V+ | Power Supply (12-24V DC) |
| **Black** | GND | Power Ground |
| **Yellow** | RS485-A | Data+ |
| **Green** | RS485-B | Data- |

## 4. Communication Settings

| Parameter | Value |
|:----------|:------|
| **Protocol** | Modbus-RTU |
| **Baud Rate** | 9600 bps |
| **Data Bits** | 8 |
| **Parity** | None |
| **Stop Bits** | 1 |
| **Default Address** | 0x01 |

## 5. Register Map

### Measurement Registers (Function 0x03)

| Address | Description | Scaling |
|:--------|:------------|:--------|
| 0x0000 | ORP Value (mV) | Direct (signed 16-bit) |

### Configuration Registers (Function 0x06)

| Address | Description | Notes |
|:--------|:------------|:------|
| 0x000A | Calibration Offset | Signed offset in mV |
| 0x0050 | Slave Address | 0x01 to 0xFE |

## 6. Reading ORP Value

Read 1 register from 0x0000:

```
Request:  01 03 00 00 00 01 84 0A
Response: 01 03 02 02 AE 38 98
```

**Decoding:**

| Hex | Decimal | Result |
|:----|:--------|:-------|
| 0x02AE | 686 | **686 mV** |

Negative values use two's complement. For example, 0xFF9C = **-100 mV**.

## 7. Single-Point Calibration

ORP uses single-point offset calibration via register 0x000A.

### Procedure

1. Prepare an ORP standard solution (e.g. +220 mV)
2. Clean the electrode with distilled water
3. Immerse in the standard solution and wait for stabilization
4. Read the current sensor value
5. Calculate the offset: `offset = standard - reading`
6. Write the offset to register 0x000A

### Example

If the standard is +220 mV and the sensor reads +200 mV, the offset is +20:

```
01 06 00 0A 00 14 A9 C7
```

If the sensor reads +240 mV, the offset is -20 (0xFFEC in two's complement):

```
01 06 00 0A FF EC E9 B5
```

## 8. Address Configuration

### Change Address (0x01 → 0x02)

```
01 06 00 50 00 02 08 1A
```

### Broadcast Discovery

Use address 0xFE with only one device connected.

## 9. Installation Notes

**Safety**

- Do not hot-plug
- Verify wiring before power
- Avoid air bubbles in measurement area

**Sensor Care**

- Clean with distilled water regularly
- Rinse with sample before measuring
- Do not touch electrode with bare hands

## Ordering Information

| Part number | Description |
|:------------|:------------|
| AGRINOVO-ORP-100 | Digital ORP Sensor |

## Revision History

| Rev | Date | Changes |
|:----|:-----|:--------|
| 1.0 | June 2026 | Initial release |
| 1.1 | August 2026 | Two-page layout; CRC values added to calibration and address examples |
| 1.2 | October 2026 | New layout |

## Contact

Agrinovo, https://agrinovo.io/products, contact@agrinovo.io, +972 54 688 8148 (direct / WhatsApp).
Specifications subject to change without notice.