Tinker&Rasor SR-2 - Range Selector; Data Logger

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107-108
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CORROSION MITIGATION INSTRUMENTATION
P. O. BOX 1667 SAN BERNARDINO, CA 92402 TEL: (909) 890-0700 FAX: (909) 890-0736
PRODUCT INSTRUCTIONS
MODEL SR-2 SOIL RESISTIVITY METER
a = pin separation
π = 3.1416
Reference: ASTM G57-95(a)
RANGE SELECTOR:
The RANGE SELECTOR switch has a lot of important information surrounding it, that the operator must
be familiar with to use the Model SR-2.
The important things to know about the area around this switch, are:
RANGE: Ohms, KOhms, MOhms
Which area is the switch in? This information will help
the operator in completing the formula for Ohm-cm.
Each position of the switch shows the RANGE, as well
as the multiplier for that RANGE.
OHM= x1
KILOHM= x1,000
MEGOHM= x1,000,000
Always move the RANGE SELECTOR switch from left to right (clockwise), stopping as soon as the LCD
display is showing an actual number.
Also, do not move from one position to the next faster than 3 seconds. The 3 second wait at each position is
necessary to ensure a proper reading. As the operator changes the position of the RANGE SELECTOR
switch, the instrument is taking reads, and this can have a small delay before the result is shown on the
LCD display.
USE WITH A SOILBOX
Tinker & Rasor offers to styles of soilbox: Model SB-1 and SB-2.
Soilbox Model SB-1 conforms to ASTM G-57 standard. Per ASTM G57, section 3.4: when using the 4 Pin
method on the SB-1, the multiplier is “1.349”. This formula is the Resistance in ohms times the cross
sectional area of the box, divided by the inner pin spacing.
When using the 2 Pin method on the Model SB-1, the multiplier is “1”.
Soilbox Model SB-2 conforms to AASHTO T-288, Fig. 2. The standard describes the method for
determining the multiplier to use in this application: 6.67 cm.
Soilboxes manufactured by a company other than Tinker & Rasor will use a multiplier determined by that
manufacturing company. It may be necessary to contact that company to obtain the correct methodology
and information.
DATA LOGGER:
The Model SR-2 has a convenient connection port for the Tinker & Rasor Model DL-1 Data Logger.
Connecting the Model DL-1 Data Logger to the Model SR-2, allows the operator to trap resistances within
the DL-1 TRAC software.