Metal Foil Current Sampling Resistor

Current sampling is an important process in many electrical applications. It involves measuring the electrical current flowing through a circuit by taking a sample of the current. To accurately perform current sampling, one needs a reliable device that can measure the current with precision. This is where metal foil resistors come in.

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Description

Current Sampling with Metal Foil Resistor

Metal foil resistors are widely used for current sampling due to their high accuracy and stability. They are made of a thin film of metal, typically nickel alloy or copper, deposited on a ceramic substrate. The metal film is then trimmed to create a precise resistance value. Metal foil resistors have a low temperature coefficient of resistance, which means that their resistance remains stable over a wide range of temperatures.

To use metal foil resistors for current sampling, they are connected in series with the circuit under test. The voltage drop across the resistor is proportional to the current flowing through the circuit, and this voltage can be measured using a voltmeter. By knowing the resistance value of the metal foil resistor and the measured voltage, the current flowing through the circuit can be calculated using Ohm's law.

Metal foil resistors are available in a wide range of resistance values and power ratings, making them suitable for different current sampling applications. They can be used in high-precision measurement instruments, as well as in industrial control systems, medical devices, and other electronic equipment.

In summary, metal foil resistors are a reliable and accurate device for current sampling. They provide precise resistance values and stable performance over a wide range of temperatures, making them suitable for various applications. If you need to measure electrical current with precision, consider using metal foil resistors for your current sampling needs.

Equivalent to ISA AH-E

Product features:

● Rated power up to 50W

● Precision of resistance value is 0.01%

● Temperature coefficient is ±2ppm/K

● Very low susceptibility

● Load stability up to 0.02%

Table 1-Parameters
Mode		RNG4617
Stopped value interval		From 0.005 to 1000Ω
power rating	The heat sink is not installed70℃	3w
	Add radiator	50w
accuracy		1%/ 0.1%/ 0.25%/ 0.5%/ 0.01%/ 0.02%/ 0.05%
Thermal resistance		1.6KW
stability (1000h)		0.02%/ 0.1%/ 0.2%/ 0.5% (It also depends on the pressure)
temperature coefficient		±10ppm/K (20 to 60℃) ±5ppm/K (20 to 60℃) ±2ppm/K (20 to 60℃)
Pressure resistance value		500VDC
Maximum current		50A
Thermoelectric potential		<1μV/K
Operating temperature interval		-40 to 130℃
Resistance material		Manganese copper, nichrome foil
placode		Anodized aluminum
Protective layer		Epoxy resin
Electrode material		Tinned copper
Pin count		4
Maximum torque		1Nm

Figure 2-Temperature coefficient

Figure 3-The reduced power curve

product-391-280

Rated Power Note-

RNG4617 Series resistance connected to a suitable radiator for use.

The maximum internal temperature is 130°C. Using the following formula:公式

Where: RθH= thermal resistance of the radiator (K / W)

RθR = electric resistance of thermal resistance (K / W)

TMAx = maximum resistance maximum working temperature

TA = Ambient temperature of radiator (℃)

P = power of resistor (W)

Figure 4-Table 4 Line connection

For low resistance resistance (less than 10 Ω), the increase in the resistance and temperature coefficient of the copper pin exceeds the resistance itself. A four-legged Kelvin connection is recommended, as shown in the figure below.

The load current on the V-pin will cause a measurement error.