AEMC 3640 User Manual

Digital Ground Resistance Tester Model 3640 and 4610 19
limitedsizeandtoreducethegroundresistivitybyperiodicallyincreasing
thesolublechemicalcontentofthesoil.
Table4showsthesubstantialreductioninresistivityofsandyloambrought
aboutbyanincreaseinchemicalsaltcontent.
0
0.1
1.0
5
10
20
10,700
1,800
460
190
130
100
The Effect of Salt* Content on the Resistivity of Soil
(sandy loam, moisture content, 15% by weight, temperature 17°C)
Added Salt
% by weight of moisture
Resistivity
(Ohm-centimeters)
Table 4
Chemicallytreatedsoilisalsosubjecttoconsiderablevariationofresistiv-
itywithchangesintemperature,asshowninTable5.
Ifsalttreatmentisemployed,itis,ofcourse,necessarytousegroundrods
whichwillresistchemicalcorrosion.
20
10
0
-5
-13
110
142
190
312
1440
The Effect of Temperature on the Resistivity of Soil Contining Salt*
(sandy loam, 20% moisture; salt 5% of weight of moisture)
Temperature °C Resistivity (Ohm-centimeters)
Table 5
*Suchascoppersulfate,sodiumcarbonateandothers.SaltsmustbeEPAorlocalordinance
approvedpriortouse.
4.1.4 Effect of Ground Rod Depth on Resistance

AEMC 3640 Specifications

General

Brand	AEMC
Model	3640
Category	Test Equipment
Language	English