The experimenters followed their experimentation with analysis of the data obtained. The experimenters first contemplated the applicability of the Probe Comp test signal to biological systems. The experimenters reasoned that the test signal was not an effective description of a biological system because the test signal did not exhibit the noise present in biological systems. While considering the observations of the oscilloscope and biological systems, the experimenters considered which settings on the oscilloscope with regard to the gain of both the probe and the oscilloscope that would be most effective in observing biological signals. Through their considerations, the experimenters concluded that the most effective settings would be 1x on the probe and 10x on the oscilloscope because (1) the experimenters reasoned that the signals obtained from biological systems would be of a low voltage and may be hidden in significant biological noise and (2) the multiplier on the probe expresses the amount of division applied to the input signal, while the multiplier on the oscilloscope expressed the amount of multiplication applied to the input from the probe; thus, the experimenters reasoned that the least amount of signal information would be lost with the conjunction of no division and 10 fold multiplication. The experimenters then considered the data exhibited in Figure 1. The experimenters concluded from the qualitative observations of the graph and the curve fits of each set of data that the voltage output range was independent of the frequency of the signal being produced. The experimenters then continued analyzing the aspects of the oscilloscope by considering the Bode plots of the AC- and the DC-coupled voltage output at various frequency as indicated in Figure 2. The experimenters believed the plots were reasonable Bode plots because the AC-coupled measurements are designed to accurately describe time-dependent signals, whereas DC-coupled measurements are designed to measure everything unselectively. As such optimizations are present, the AC should effectively express time-dependent signals, but does not effectively express signals that have no time dependence (i.e., DC offset). Thus, the experimenters reasoned that the AC-coupling plot should exhibit high-pass filter characteristics. On the other hand, because DC is designed to obtain the entirety of the signal, the DC-coupling plot should exhibit all-pass filter characteristics. The experimenters noted that the plots observed in Figure 2 took those forms, and, thus, the experimenters concluded the data was effective and acceptable. The experimenters then turned their attention to analysis of the operational amplifiers and differential gain. In doing so, the experimenters considered the effect of RG on the INA118 instrumentation amplifier and concluded the absence of RG would be significantly detrimental to the function of the amplifier. This detriment was anticipated because the resistor RG enabled feedback between the two unity gain buffers present in INA118, and, as such, the removal of the resistor would not enable the voltage differences to be buffered from environmental factors. The experimenters also concluded that the removal of the resistor converted the instrumentation amplifier to a differential gain amplifier similar to the INA137 operational amplifier. As such was their conclusion, the experimenters considered any inherent advantages or disadvantages with each amplifier. According to the Burr-Brown Corporation, the INA137 differential gain amplifier has an input impedance of 24 kΩ and CMRR of approximately 31,600 whereas Texas Instruments asserts that the INA118 instrumentation amplifier has an input impedance of 10 MΩ and a CMRR of approximately 316,000. The experimenters noted
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That being said, the experimenters noted some values to be inconsistent with the accepted values, namely the values obtained for the CMRR of each amplifier, as the CMRR values were significantly lower than the accepted values, and the CMRR value for the instrumentation amplifier was less than the CMRR value for the differential gain amplifier, as the converse is supposed to be true. The experimenters believed that equipment capabilities or noise in the environment and circuit may have contributed to the inconsistency of the data collected to the accepted values. The experiment could be performed in a Faraday cage, as such a device would diminish the noise observed by the experimenters as originating from both the oscilloscope and themselves. Further investigation may also be required to ascertain the source of this
That being said, the experimenters noted some values to be inconsistent with the accepted values, namely the values obtained for the CMRR of each amplifier, as the CMRR values were significantly lower than the accepted values, and the CMRR value for the instrumentation amplifier was less than the CMRR value for the differential gain amplifier, as the converse is supposed to be true. The experimenters believed that equipment capabilities or noise in the environment and circuit may have contributed to the inconsistency of the data collected to the accepted values. The experiment could be performed in a Faraday cage, as such a device would diminish the noise observed by the experimenters as originating from both the oscilloscope and themselves. Further investigation may also be required to ascertain the source of this