Resistor testing

Electrochemical Impedance Spectroscopy (EIS) and AC Impedance Many direct-current test techniques assess the overall corrosion process occurring at a metal surface, but treat the metal/ solution interface as if it were a pure resistor. Problems of accuracy and reproducibility frequently encountered in the application of direct-current methods have led to increasing use of electrochemical impedance spectroscopy (EIS). 

Above Electrical test system. The four fixed resistors... 

One temperature-sensitive resistor as compensator and another one as detector are integrated into adjoining strings of a Wheatstone bridge circuit the voltage can be measured. Since both resistors are exposed to the test gas flow, disturbances caused by changes in temperature and humidity are compensated. 

Function verification of user program written in Labview — We designed a simple device that uses a chart recorder, a battery, and four resistors to verify that the program performs as intended. Each arm of the programming tree was tested using different parameter entries. Figure 4.16 presents the raw data from one of the experiments. 

The following chapter includes the description of different types of microhotplates that feature resistor and transistor heating elements. Three of them were specifically designed to be monolithically integrated with circuitry, and one was a testing device that was used for the assessment of temperature distributions on the microhotplates. 

First chemical test measurements have been conducted with the array chip. Figure 6.19 shows the results that have been obtained simultaneously from three microhotplates coated with different tin-dioxide-based materials at operation temperatures of 280 °C and 330 °C in humidified air (40% relative humidity at 22 °C). The first microhotplate (pHPl) is covered with a Pd-doped Sn02 layer (0.2wt% Pd), which is optimized for CO-detection, whereas the sensitive layer on microhotplate 3 contains 3 wt% Pd, which renders this material more responsive to CH4. The material on microhotplate 2 is pure tin oxide, which is known to be sensitive to NO2. Therefore, the electrodes on microhotplate 2 do not measure any significant response upon exposure to CO or methane. The digital register values can be converted to resistance values by taking into account the resistor bias currents [147,148]. The calculated baseline resistance of microhotplate 1 is approximately 47 kQ, that of hotplate 2 is 370 kQ and the material on hotplate 3 features a rather large resistance of nearly 1MQ. 

EIS data is generally interpreted based on defining an appropriate equivalent circuit model that best fits the acquired data. The elements of the circuit model involve a specific arrangement of resistors, capacitors, and inductors that tacitly represent the physicochemical reality of the device under test. Under these circumstances the numerical value for chemical properties of the system can be extracted by fitting the data to the equivalent circuit model. Impedance measurements are typically described by one of two models ... 

Then we decided to try using the DC of the Microwave Transformer set. We wired in the bank of diodes that had been used with the microwave transformer and its capacitor (a 10.000 volt oil filled) before our bank of diodes. We put in a current-limiting resistor between our bank of diodes and the microwave s bank after the capacitor. We started with 1000 ohms here and gradually reduced it down to about 40 ohms (we where afraid to go lower for fear of blowing our diode bank). Each time we reduced it and tested it we got a louder bang when the spark occurred. At one point we had two 500 ohm resistors in parallel and one opened up. This was the loudest bang of... 

I have done a little testing at maybe 7 bar - till it started arcing in the rectifier. Current problem is specifying the adder diodes - direction, count, etc. I am using 1 KV 75 nS Trr - quick recovery diodes, costing. 09 each, in parallel with 1.5 M 1/2 W metal film 1% resistors. 

Triple-track resistor and conductor coupons are made by deposition of Ta2N and Ti-Pd-Au metallization, respectively, on the AI2O3 substrate. This test pattern consists of three parallel meandering lines with 3-mil spaces between lines. Each line is approximately 3-mil wide and has 2.86 X ]0 squares, with an overall length of 8.5 in. The number of squares of insulator between adjacent lines is approximately 3.5 X 10". ... 

Figure 5. Triple-track resistor electrical testing performance of crown ethers in commercial RTV silicon encapsulants. Conditions bias, 180 V relative humidity, 96% temperature, 100°C.

EXERCISE 5-111 Find the magnitude and phase of the voltage Vo for frequencies from 10 Hz to 1 kHz. Note that LI is coupled to L2, but L3 is not coupled to either LI or L2. The 100 G 2 resistor is used to isolate the two loops. In an actual circuit there would not be a connection between the two loops. However, PSpice requires all portions of a circuit to be referenced to ground. If the 100 G 2 resistor were replaced by an open circuit, the circuit would still function in the same way if tested in the lab, but the right loop would not have a ground reference. Without the 100 G 2 resistor, PSpice will generate an error message and will not simulate the circuit. 

The circuitry used for the breadboard testing of NO and NOp sensor cells was very similar to that shown in Figure 2 only the applied potential was changed. An applied potential of +1.30 V versus the SHE reference electrode was used for NO oxidation while a potential of 0.75 V versus the same reference electrode was used for N02 reduction. Current measurements were again made by measuring the voltage drop across resistor RA. Three electrode systems were used for both gases. 

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