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80" diameter current clamp
Overview
Swain Meter DC Amp Clips™ and DC Amp Clamps™
are current clip and clamp sensors which are calibrated and sold as a
set with Swain Meters. All Swain meters offer Magnetic Error Reduction (MER)
technology, which minimizes errors due to the magnetic field of
the Earth and surrounding iron or steel structures. Two sensor
technologies are offered:
- MER Sensors. These
utilize the older and less expensive Magnetic Error Reduction (MER)
technology.
- MER2
Sensors. These utilize the newer, patented MER2 sensor
technology, which reduces magnetic interference by a factor of 2 or
3 and cuts zero errors in half compared to MER.
Two meters are compatible Swain Sensors:
- MER Meter® Digital DC Ammeter
with Magnetic Error Correction
- AutoMer™
Autoranging Digital DC ammeter with Magnetic Error Correction
Capabilities of DC Amp
Clips & Clamps
-
 Suitable
for use in high-noise environments
of power plants.
- Currents in URD concentric neutral,
pump shafts, and transmission pipe can be measured while in service.
- Differential leakage current, even
current flowing inside steel conduit, may be measured.
- Interference current can be recorded
using a recorder jack which multiplies the unattended meter span by
up to 5 times.
- If two or more conductors are in the
aperture of a sensor, the reading is the algebraic sum of all
currents.
- The indicator shows the average
magnitude of current whether it is DC, pulsating, AC, or a
combination.
- Alternating current is rejected so
that 10 amp. AC interference will change a measurement less than 5
mA.
- A brief 200A overload on any range
will not alter the zero or damage the meter.
- Accuracy is good even if a conductor
is not centered in the aperture of the sensor.
- Current flowing outside the sensor
is rejected.
Measurement Examples
- Car battery current with the cable
connected normally. Parasitic drain, charging and cranking current
are shown without the need to disconnect a cable.
- Power plant battery float charge and
load current with the battery on line and connected.
- 4-20 mA loop current with the
control on line, with no need to break the current loop.
- Sacrificial or impressed anode
current by clipping around the cable. No need to open the cable or
add shunts which would increase resistance and could blow with
lightning. Likewise with bonds.
- Interference current in a large gas
pipe, steel reinforced concrete column, or telephone cable with the
line in service.
- Flange leakage current in an
operating gas, oil or water pipe.
- Foreign contact or ground faults are
located when other devices fail.
- Offshore platform aluminum anode
current at depths of hundreds of feet to show that electrical
contact is good and the anode will last.
- Current in a propeller or pump shaft
while the shaft is rotating.
- Guy wire or anchor rod current drain
to ground when only a short section is handy.
- Electrolytic current flowing in
brine in a pipe or in salt water.
- Algebraic sum of current in a steel
conduit plus the current in conductors inside the conduit by
clipping over the outside of the conduit.
- Differential control line leak to
ground and fault location with the line operating.
- URD bare outer conductor resistance
to find local corrosion, with the cable live and in service.
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