Tel: (909) 890-0700
Fax: (909) 890-0736
P.
O.
B
OX
1667
S
AN
B
ERNARDINO
,
C
A
92402
Web: www.tinker-rasor.com
E-mail: [email protected]
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Sponsoring members of NACE International, NACE Foundation
QMF-570
112-071
P
RODUCT
I
NSTRUCTIONS
IMPORTANT NOTE: Do not use this instrument in an explosive environment.
DESCRIPTION
The Model RF/IT Insulator Tester is a highly sensitive device, designed to test above ground pipeline insulators
individually to determine their effectiveness. The Model RF/IT Insulator Tester is effective in the testing of pipeline
insulators in parallel or series installations, even if one or more of the insulators are not operating properly. The
tests conducted are fast and accurate.
METHOD
Two common methods used to measure a pipeline insulator are DC resistance and Radio Frequency Skin Effect.
Radio Frequency Skin Effect is the phenomenon where the apparent resistance of a conductor increases as the
frequency increases. With DC, the charge carriers have an even distribution throughout the area of the conductor.
However, as the frequency increases, the charge carriers subsequently move towards the edge of the wire,
decreasing the effective area and increasing the apparent resistance.
Because the Radio Frequency meter does not use a DC voltage, it is unaffected by DC or AC voltages under 50
volts and there is no need to disconnect the cathodic protection voltage applied to the pipe and/or structure.
Another advantage of the skin effect is that errors due to diameter, relative permeability of the pipe and insulator
distance are negligible.
To measure an insulator using the Radio Frequency method is similar to that of the DC measurement. The probes
are placed across the insulator and the technician reads the display. Maximum deflection of the meter (100 or all
the way to the Right) indicates a resistance of a high enough value as to indicate a good insulator, whereas if the
insulator is shorted or has a low electrical resistance, the meter will only show reads to the left of top center (older
analog meter shows one or two bars from the Left).
EQUIPMENT
The Model RF/IT Insulator Tester consists of a portable battery powered electronic instrument with detachable
probes for making positive electrical contact across the insulator. The instrument is packaged in a plastic case
complete with batteries ready to operate. Two extra steel needle points are supplied with the Tester (stored in a
small bag between foam insert and instrument lid).
Due to the design and method of operation, a certificate of calibration with traceability to NIST standards is not
available for this equipment. A certificate of calibration showing test results with a statement of conformity can be
provided upon request at time of purchase or repair. The RF/IT is recommended for annual inspection by Tinker &
Rasor trained repair technicians.
The Model RF/IT Insulator Tester is factory tuned and needs no field adjustments. The length and size of the
probe wire conductors are critical to the tuning and performance of the Model RF/IT Tester.
Do not make
changes or substitutes for probes & wires
.
Push the “RED” button on the panel to turn the Tester “ON”. Push again for the “OFF” position. If tester is not
turned off manually, it will turn off automatically after 10 minutes. If Tester seems to fail during testing, the first
thing to check is the “ON-OFF” switch. The built-in timer is designed to save batteries in case the operator fails to
turn the Tester “OFF” after each usage.