Contents

Revision and Copyright Information
Warranty
Assistance
Table of Contents
1. Introduction
2. Cautionary Statements
3. Initial Inspection
4. Quickstart
- 4.1 Installation
- 4.2 Use SCWin to Program Datalogger and Generate Wiring Diagram
5. Overview
6. Specifications
7. Operation
- 7.1 Wiring
- 7.2 Programming
  - 7.2.1 Excite and Measure the 227
  - 7.2.2 Calculate Sensor Resistance
  - 7.2.3 Calculate Soil Water Potential
  - 7.2.4 Programming Examples
    - 7.2.4.1 Example CR1000 Program
    - 7.2.4.2 Example CR10(X) Program
Campbell Scientific Companies

Campbell Scientific 227-L Instruction Manual

Campbell Scientific 227-L Gypsum Block manual cover

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Campbell Scientific 227-L Gypsum Block Specification

The Campbell Scientific 227-L Gypsum Block is a robust soil moisture sensor designed for agricultural and environmental research applications. It utilizes the electrical resistance method to measure soil water potential, offering an effective solution for monitoring soil moisture levels in various soil types. The sensor consists of two electrodes embedded in a gypsum block, which absorbs water from the surrounding soil, allowing the measurement of the soil's water potential based on changes in electrical resistance.

The 227-L is known for its durability and reliability, with the gypsum block providing a stable medium that responds to moisture variations. This sensor is ideal for long-term soil moisture studies due to its resistance to degradation in the field. The standard cable length of the 227-L is 15 feet, but it can be customized according to specific installation requirements, ensuring flexibility in diverse experimental setups.

The operating temperature range for the 227-L is -25 to 70 degrees Celsius, making it suitable for a wide range of environmental conditions. Its compatibility with Campbell Scientific data loggers enables seamless integration into existing measurement systems, facilitating real-time data acquisition and analysis. The sensor typically requires minimal maintenance, although calibration may be necessary to account for soil-specific characteristics.

The Campbell Scientific 227-L Gypsum Block is a cost-effective solution for researchers and agricultural professionals seeking to enhance their understanding of soil moisture dynamics. Its straightforward design and reliable performance make it an essential tool for optimizing water management practices and improving crop yields.

Campbell Scientific 227-L Gypsum Block F.A.Q.

How do I install the Campbell Scientific 227-L Gypsum Block in the field?

To install the 227-L Gypsum Block, dig a hole at the desired depth, soak the block in water until saturated, place it in the hole, and backfill with soil, ensuring good contact between the block and soil.

What is the recommended maintenance schedule for the 227-L Gypsum Block?

The 227-L Gypsum Block requires minimal maintenance, but it should be inspected annually for physical damage and replaced if necessary. Additionally, check for proper soil contact and saturation.

How does the 227-L Gypsum Block measure soil moisture?

The 227-L Gypsum Block measures soil moisture by detecting changes in electrical resistance between electrodes embedded in the gypsum, which varies with moisture content.

What should I do if the 227-L Gypsum Block gives erratic readings?

Check for proper installation and ensure good soil contact. Erratic readings can also result from damaged blocks or poor connections. Reinstall or replace the block if necessary.

Can the 227-L Gypsum Block be used in all soil types?

The 227-L Gypsum Block is suitable for most soil types, but extremely sandy or rocky soils may affect its accuracy. Proper installation is crucial for reliable readings.

How do I connect the 227-L Gypsum Block to a data logger?

Connect the leads from the 227-L Gypsum Block to the compatible input channels on your data logger, following the manufacturer's wiring guidelines and ensuring secure connections.

What is the typical lifespan of a 227-L Gypsum Block?

The typical lifespan of a 227-L Gypsum Block is 1 to 3 years, depending on soil conditions and usage. Regular inspection helps maximize its lifespan.

How do I interpret the resistance readings from the 227-L Gypsum Block?

Resistance readings are inversely proportional to soil moisture. Higher resistance indicates drier soil, while lower resistance indicates wetter soil. Calibration may be needed for precise measurements.

What factors can affect the accuracy of the 227-L Gypsum Block?

Accuracy can be affected by improper installation, soil type, temperature fluctuations, and physical wear. Regular checks and proper calibration can mitigate these issues.

Is it necessary to calibrate the 227-L Gypsum Block?

Calibration is not mandatory but is recommended for higher accuracy, especially in research applications. This involves correlating resistance readings with known moisture levels.