Large Soil Box
Our Large Soil Box, which has a 270 ml (270 cm³) volume is compatible with 4-Terminal Resistance Meters such as the Miller 400A, the Miller 400D and the Nilsson 400 Resistance Meters.
Miller Soil Boxes can be used to satisfy either the 4-electrode method (ASTM G57 Standard) or the 2-electrode methods (ASTM G187 or AASHTO T-288 Standards).
For the 2-electrode method, the two interior pins are removed which changes the multiplication factor from 1cm (for the 4-electrode method) to either 0.67 cm for the small box or to 0.57 cm for the large box. Please see the following link for details: ASTM G57 and AASHTO T-288 Standard Methodologies.
- Plexiglas body with rounded corners for easy cleaning
- Stainless steel current distribution plates and removable brass pins (potential measurement pins)
Critical Dimensions (for 4-electrode method, i.e. the two interior pins are in use): The soil boxes are designed such that the cross-sectional area of the soil (or liquid) sample (A), with the box filled level, divided by the separation between the pins (L) is equal to 1 cm.
- Cross-sectional area = 4 cm x 3.2 cm = 12.8 cm²
- Pin separation = 12.8cm
- A / L = 1 cm
Soil Box Example: M.C.Miller Factory Tap Water
|Measured Resistance||= 1.97 kΩ|
|Resistivity Value||= 1.97 kΩ x 1 cm|
|= 1,970 Ω.cm|
|[Hence, MCM Water Conductivity = 507 µS/cm]|
- Overall Length (with terminals in place): 11 inches (28 cm)
- Overall Width (with terminals in place): 3 inches (7.6 cm)
- Height: 1.5 inches (3.81 cm)
- Interior Volume: 270 ml (270 cm³) (16.476 in³)