13
will not have a large affect on the reading but will de-
crease the chances the rods will be bent or broken. Like-
wise, it is best to avoid areas with rocks or other material
that can cause the rods to deflect or bend. If the ground
is especially hard or compact, you can use a Pilot Hole
maker (item 6430PH) to make 1½” holes to aid in start-
ing the insertion of the probe rods.
- Press the
READ
button to initiate the measurement se-
quence. The reading should appear almost instantane-
ously.
Note:
The TDR rods are manufactured from type 303
stainless steel and are designed to bend if non-vertical
force is applied to them. This serves to protect the TDR
block electronics from potential damage that could be
caused by excessive force.
Occasional rod bending is normal, and can be expected
during the course of sampling. Longer rods will be more
susceptible to bending than shorter rods. If bending oc-
curs, rods should simply be bent back to parallel position,
perpendicular to the TDR block. Measurements will
continue to be accurate provided that rods are reasonably
close to parallel.
If care is not taken to reposition rods to a parallel posi-
tion, subsequent pressure on the rods will accentuate the
bending and may cause the rods to break. Rods should
be considered maintenance items that may need to be re-
placed over time, depending upon the nature and fre-
quency of sampling.