Changes between Version 206 and Version 207 of WikiStart


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Oct 18, 2016, 4:22:52 PM (4 years ago)
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peakall3je
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    113113
    114114'''PME Microscale Conductivity and Temperature Instrument (MSCTI)'''
    115 The MicroScale Conductivity and Temperature Instrument (MSCTI) is designed to measure the electrical conductivity and temperature of solutions containing conductive ions. This instrument provides two analog outputs, one linearly proportional to the solution conductivity, and one non-linearly proportional to the solution temperature. One probe is positioned on the traverse, alongside the ADVs, whilst a second probe is positioned at the base of the input box. For the main experiments, the conductivity probe in the channel is located 7.3 cm downstream from ADV1, and is offset by 5.5 cm such that its initial position is 20.5 cm from the wall. The second conductivity probe, positioned in the header box, is situated in the middle of the box and is approximately 1.5 cm above the floor. The MSCTI outputs two continuous voltage signals, one for conductivity and one for temperature, and these are recorded as part of the LVM file [C0 and T0 are conductivity and temperature for the probe on the traverse (though T0 does not work, since that part of the instrument is broken), and C1 and T1 are conductivity and temperature from the probe mounted in the inlet box]. We briefly had a second probe [just C2] in the inlet but this broke when it was damaged by a large input flow. Later files continue to have C2, but these just consist of noise. The probes are calibrated after each drain. To calibrate, samples of different densities (as measured with the hand-held Anton Paar density meter) are prepared at a given temperature of 21-22C and these are compared to the voltage output for conductivity of each probe. Because the water is so constant in the experiments, around 21-22C then this calibration approach enables a direct correlation between the voltage representing conductivity, and flow density. As such the temperature output from the two probes (note again that T0 is broken) are not required.
     115The MicroScale Conductivity and Temperature Instrument (MSCTI) is designed to measure the electrical conductivity and temperature of solutions containing conductive ions. This instrument provides two analog outputs, one linearly proportional to the solution conductivity, and one non-linearly proportional to the solution temperature. One probe is positioned on the traverse, alongside the ADVs, whilst a second probe is positioned at the base of the input box. For the main experiments, the conductivity probe in the channel is located 7.3 cm downstream from ADV1, and is offset by 5.5 cm such that its initial position is 20.5 cm from the wall. The second conductivity probe, positioned in the header box, is situated in the middle of the box and is approximately 1.5 cm above the floor. The MSCTI outputs two continuous voltage signals, one for conductivity and one for temperature, and these are recorded as part of the LVM file [C0 and T0 are conductivity and temperature for the probe on the traverse (though T0 does not work, since that part of the instrument is broken), and C1 and T1 are conductivity and temperature from the probe mounted in the inlet box]. We briefly had a second probe [just C2] in the inlet but this broke when it was damaged by a large input flow. Later files continue to have C2, but these just consist of noise. The probes are calibrated after each drain. To calibrate, samples of different densities (as measured with the hand-held Anton Paar density meter) are prepared at a given temperature of 21-22C and these are compared to the voltage output for conductivity of each probe. Because the water is so constant in the experiments, around 21-22C then this calibration approach enables a direct correlation between the voltage representing conductivity, and flow density. As such the temperature output from the two probes (note again that T0 is broken) are not required.The effects of temperature are small, a 1C change in temperature for fresh water changes the conductivity by only 2% (see Barron and Ashton, Reagecon Technical Paper).
    116116
    117117'''Particle Imaging Velocimetry (PIV)'''