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Description
The Current sensor 0222i is designed for measuring small currents in AC and DC
circuits in the range between -500 and +500 mA. It has two banana (4-mm) plugs
for easy connection.
The sensor contains a sensing element and a signal-conditioning amplifier. The
sensing element is a 0.4
resistor (0.3 W) connected between the red and black
terminals. As the current passes through the resistor, a small potential difference can
be measured across this resistor. This potential difference goes through a signal
amplifier and the output of the sensor is adjusted to the range of
7.5V, which can
be measured by an interface. The sensor is protected by a multifuse (resistance of 0.9
). The time to trip the multifuse to a high-resistant state is 0.1 sec. at 5 A.
The sensor should be connected in series to a circuit element. Currents in either
direction can be measured. The current is indicated as positive when it flows from
the red terminal to the black terminal.
The Current sensor is equipped with a BT plug and can be connected to the
following CMA interfaces: €Lab
,
CoachLab II/II
+
and
U
LAB. Furthermore the
sensor can be used with Texas Instruments CBL
, CBL2
and Vernier LabPro.
Sensor specifications
The Current sensor has a memory chip (EEPROM) with information about the
sensor. Through a simple protocol (I
2
C) the sensor transfers its data: name, quantity,
unit and calibration to the interface
1
.
Examples of experiments
The Current sensor is specially designed for measurements of very low and accurate
currents. It can be used in various experiments such as:
characteristics of a light bulb and a diode,
measurements of internal resonance and EMF,
measurements in series and parallel electrical circuits.
Together with a Differential Voltage Sensor it can be used to explore the
relationship between the current and the voltage in electrical circuits - the Ohm’s
Law.
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This is valid for the following interfaces: CMA €Lab
,
BT inputs of CoachLab II/II
+
and
U
LAB,
TI CBL
and CBL2
, and Vernier LabPro.
