1. An ion trap mass spectrometer comprising:
an ion trap to confine ions in a space surrounded by three or more electrodes;
a positive voltage DC power supply;
a negative voltage DC power supply;
a switch on a positive electrode side that turns on and off the positive voltage output from said positive voltage DC power supply;
a switch on a negative electrode side that turns on and off the negative voltage output from said negative voltage DC power supply;
a square-wave voltage generation means for outputting a square-wave voltage to at least one of said electrodes by using the positive and negative voltages supplied through each of said switches on both positive and negative electrode sides when such switches are on, for trapping ions;
a positive electrode side waveform area calculation means for calculating the area of the square-wave voltage on the positive electrode side that is applied to at least one of said electrodes;
a negative electrode side waveform area calculation means for calculating the area of the square-wave voltage on the negative electrode side that is applied to at least one of said electrodes; and
a feedback adjusting means for adjusting the timing of change of at least one of control signals that turn on and off said switches on the positive and negative electrode sides in order to level the areas calculated by said positive electrode side waveform area calculation means and negative electrode side waveform area calculation means.
2. The ion trap mass spectrometer according to claim 1, further comprising:
a peak value feedback adjusting means for adjusting voltages output from said positive and negative voltage DC power supplies by feedback so that peak values of said square-wave voltages on the positive and negative electrode sides become their respective predetermined value.
3. The ion trap mass spectrometer according to claim 1,
wherein said positive electrode side waveform area calculation means and said negative electrode side waveform area calculation means respectively include a rectifying means for separating waveforms only on either positive or negative electrode side from a bipolar square waveform and an integrating means for integrating such separated square waveforms only on either the positive or negative electrode side,
wherein said feedback adjusting means adjusts the timing of change of at least one of control signals that turn on and off said switches on the positive and negative electrode sides so that the difference of output between the two integrating means from the respective waveform area calculation means becomes zero.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A roofing member having thermal expansion relief capabilities when mounted onto a roof surface in laterally extending courses, comprising:
a main body having side regions, a top surface and a bottom surface, wherein the bottom surface is formed with one or more depressions each positioned proximal to one of the side regions; and
one or more spacer tabs each extending outwardly from at least one of the side regions of the main body adjacent to one depression of the one or more depressions;
wherein a compressive force against a particular one of the spacer tabs of the roofing member caused by thermal expansion of an adjacent roofing member when such roofing members are both mounted in the same course causes failure of the respective main body side region at a location adjacent to the particular spacer tab of the roofing member such that the particular spacer tab is
at least partially displaced into one of the depressions adjacent to the particular spacer tab,
wherein the one or more spacer tabs and the respective adjacent one or more depressions are configured such that failure of the respective main body side region at a location adjacent to the particular spacer tab resulting from the compressive force against the particular spacer tab occurs as a first mode of failure whereby the particular spacer tab cantilevers into the respective depression, and wherein the failure of the respective main body side region at a location adjacent to the particular spacer tab resulting from the compressive force against the particular spacer tab further occurs as a second mode of failure whereby the particular spacer tab fully separates from the main body and is displaced inwardly from the position of the spacer tab at the first mode of failure.
2. The roofing member of claim 1, wherein the one or more spacer tabs and the respective adjacent one or more depressions are configured such that a first compressive force against a particular one of the spacer tabs of the roofing member causes the particular spacer tab to be partially displaced into the respective depression adjacent to the particular spacer tab and a second compressive force against the particular spacer tab causes the particular spacer tab to be fully displaced into the respective depression adjacent to the particular spacer tab.
3. A roofing member, comprising:
a main body having side regions, a top surface and a bottom surface, wherein the bottom surface is formed with a depression feature positioned proximal to at least one of the side regions; and
a spacer tab feature extending outwardly from at least one of the side regions of the main body adjacent to the depression feature;
wherein the spacer tab feature and the depression feature cooperatively provide stress relief through movement of the spacer tab feature at least partially into the depression feature upon a sufficient lateral compressive force being applied to the spacer tab feature inwardly with respect to one of the side regions of the main body, wherein the depression feature is configured to form a first wall thickness between a first portion of the depression feature and the respective main body side region positioned proximally thereto at a first longitudinal end of the spacer tab feature, and a second wall thickness between a second portion of the depression feature and the respective main body side region positioned proximally thereto at a second longitudinal end of the spacer tab feature, enabling the stress relief movement of the spacer tab feature to result from failure of the first wall thickness upon the compressive force being directed inwardly in the transverse direction, and wherein the first longitudinal end of the spacer tab feature presents a sloped intersection edge with the respective main body side region to form an increasing longitudinal dimension for the spacer tab feature moving in the direction of the main body bottom surface.
4. The roofing member of claim 3, wherein the depression feature is configured to fully receive the spacer tab feature upon a second sufficient compressive force being applied to the spacer tab feature inwardly with respect to one of the side regions of the main body.
5. The roofing member of claim 3, wherein the main body has a pair of side regions and the depression feature is positioned proximal to both of the side regions, and wherein the spacer tab feature extends outwardly from both of the side regions.
6. The roofing member of claim 3, wherein each of the side regions form a sidewall, and the spacer tab feature extends outwardly from each of the sidewalls.