Metal Strip Current Sense Resistors

To measure resistance:
 Turn power to circuit OFF.
• If a circuit includes a capacitor, discharge the capacitor before taking any resistance reading.

 Turn digital multimeter dial to resistance, or ohms, which often shares a spot on the dial with one or more other test/measurement modes (continuity, capacitance or diode; see illustration below).
• The display should show OLΩ because, in Resistance mode, even before test leads are connected to a component, a digital multimeter automatically begins taking a resistance measurement.
• The MΩ symbol may appear in the display because the resistance of open (unattached) test leads is very high.
• When the leads are connected to a component, a digital multimeter automatically uses the Autorange mode to adjust to the best range.
• Pressing the Range button allows a technician to manually set the range.
• Best results will be achieved if the component to be tested is removed from the circuit. If the component is left in the circuit, the readings could be affected by other components in parallel with the component to be tested.

 First insert the black test lead into the COM jack.

 Then insert the red lead into the VΩ jack.
• When finished, remove the leads in reverse order: red first, then black.

 Connect test leads across the component being tested.
• Make sure that contact between the test leads and circuit is good.

Tip: For very low-resistance measurements, use the relative mode (REL; see point 11). It may also be referred to as zero or Delta (Δ) mode. It automatically subtracts test lead resistance—typically 0.2 Ω to 0.5 Ω. Ideally, if test leads touch (are shorted together), the display should show 0 Ω.
Other factors that can affect resistance readings: Foreign substances (dirt, solder flux, oil), body contact with the metal ends of the test leads, or parallel circuit paths. The human body becomes a parallel resistance path, lowering total circuit resistance. Thus, avoid touching metal parts of test leads to avoid errors.

 Read the measurement on the display.

 When finished, turn the multimeter OFF to prevent battery drain.
Advanced digital multimeter options

  Press the RANGE button to select a specific fixed measurement range.
• Be sure to note the annunciator (such as K or M) after the measurement in the display.

 Press the HOLD button to capture a stable measurement—it can be viewed later.

 Press the MIN/MAX button to capture the lowest and highest measurement.
• The multimeter beeps each time a new reading is recorded.

 Press the relative (REL) button to set the multimeter to a specific reference value.
• Measurements above and below the reference value are displayed.

Wire wound resistor
A form of a passive component is called a wire-wound resistor. A wire wound resistor is created by wrapping metal wire around a metal core. The metal wire serves as the electric current’s resistive component. Thus, the metal wire restricts a specific level of electric current. As a non-conductive substance, the metal core is placed. As a result, it blocks the flow of electric current.

Foil resistor
The most precise and reliable parts to employ to limit the flow of electric current to a specific level are foil resistors. Compared to other types of resistors, foil resistors generate little noise. The TCR (Temperature Coefficient of Resistance) of foil resistors is low.

Carbon composition resistor
A passive component that limits the flow of electric current to a set level is a resistor made of carbon called a carbon composition resistor. The cylindrical resistive element used to create the carbon composition resistors has integrated metal end caps. The ceramic and carbon powder combination is used to create the cylindrical resistive element of the carbon composition resistor. The carbon powder effectively conducts electric current.

Carbon film resistor
The carbon film resistor is the most common type of resistor used in electrical circuits. The carbon film is applied to a ceramic substrate to create the carbon film resistors. The ceramic substrate serves as an electrical current insulator, while the carbon sheet functions as a resistive element to the current.

Metal film resistor
A form of a passive component known as a metal film resistor uses metal film to limit the flow of electric current to a specific level. In contrast to metal film resistors, which use chromium, nickel, tin, and antimony to create their films, carbon is used to create the film in carbon film resistors. The TCR (temperature coefficient of resistance) of metal film resistors is low.

Metal glaze resistor
The metal glaze resistor is a passive component used to limit the flow of electric current to a certain level by combining glass powder with metal particles. Low TCR (temperature coefficient of resistance) for metal glaze resistors.

Metal oxide film resistor
A form of a passive component known as a metal oxide film resistor uses metal oxide film as the resistive element to limit the flow of electric current to a specific level. Metal oxide film resistor construction is virtually identical to metal film resistors.