MC Miller Soil Boxes
MC Miller Soil Boxes
MC Miller’s “Large Soil Box” #37008, which has a 270 ml (270 cubic cm) volume is compatible with 4-Terminal Resistance Meters such as the Miller 400A, the Miller 400D, and the Nilsson 400 Resistance Meters.
Miller’s “Small Soil Box” #37006, has an 80 ml (80 cubic cm) volume and is compatible with 4-Terminal Resistance Meters such as the Miller 400A, the Miller 400D, and the Nilsson 400 Resistance Meters.
MC Miller Soil Boxes can be used to satisfy either the 4-electrode method (ASTMG57 Standard) or the 2-electrode methods (ASTM G187 or AASHTO T-288 Standards). For the 2-electrode method, the two interior pins are removed that changes the multiplication factor from 1cm (for the 4-electrode method) to either 0.67cm for the small box or to 0.57 cm for the large box.
Construction Materials:
- 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) 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 = 12.8 cm
- A/L = 1 cm
Soil Box Example: MC Miller Factory Tap Water
Measured Resistance = 1.97 kΩ
Resistivity Value = 1.97kΩx 1 cm
= 1,970 Ω.cm
Large box (Cat #37008):
- 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 cubic cm)
Small box (Cat #37006):
- Overall Length (with terminals in place): 6.25 inches (15.87 cm)
- Overall Width (with terminals in place): 2.5 inches (6.35 cm)
- Height: 1.25 inches (3.17 cm)
- Interior Volume: 80 ml (80 cubic cm)
