CN208795802U - A kind of improvement device based on Millikan oil drop instrument - Google Patents

Abstract

The utility model relates to a kind of measuring devices of droplet carried charge, belong to the field of measuring technique of electron spray droplet carrying capacity.Major function is that the rapid survey of multiple droplet carried charges is realized under the conditions of primary atomization.Its key technology, which essentially consists in, solves the problems, such as that traditional Millikan oil drop instrument test measurement data sheet one and balanced voltage are difficult to adjust.The measuring device specifically includes that annular electrode, Teflon insulating materials, insulation droplet box, CCD television microscope and rack-and-pinion lifting platform；It is distributed between adjacent insulation droplet box at constant gradient, different electric field strengths is constructed under same operating voltage, the position of CCD camera is adjusted by rack-and-pinion lifting platform, and then the motion profile of the Charged Droplet in each electric field is recorded, and observed and measured one by one, so that the measurement time used be greatly saved on the whole.

Description

A kind of improvement device based on Millikan oil drop instrument

Technical field

The utility model relates to the field of measuring technique of electron spray droplet carried charge.Specifically related to based on multiple electric-field strengths Degree carries out region division to range of atomization is formed by, and then to the dress that the Charged Droplet in each region is observed and measured one by one It sets.

Background technique

The charged effect of droplet is particularly critical in electrospray techniques, it not only influences whether the size of droplet, motion profile, It is simultaneously also the important parameter of evaluation electron spray atomizing effect.Therefore for electrospray techniques, carried charge is carried out to droplet Measurement is particularly important.

The measurement method of known several static contents has Millikan oil drop instrument method, Faraday cup method and netted goal method. Millikan oil drop instrument method relative to other two methods measurement accuracy with higher, and test process and pertinent instruments also compared with To be perfect, but this method be rarely employed in electrospray techniques, the carried charge of droplet is measured.To find out its cause, mainly Since traditional Millikan oil drop instrument method is a kind of method measured for single drop, and the formation mechenism of electron spray is different Often complicated, being in most cases formed by droplet, not only number is various, and size, carried charge are different.Single mist The carried charge of drop is not enough to characterize the average level of the droplet carried charge in entire atomization field, can not reflect existing atomization condition Under atomizing effect.Therefore, how using the rapid survey that Millikan oil drop instrument method carries out multiple droplet carried charges to become it Whether the key point on electrospray techniques can be applied effectively.

Utility model content

In order to overcome the problems, such as that Millikan oil drop test measurement data under the conditions of primary atomization is monistic, the utility model Be designed to provide a kind of measuring device that can quickly determines and be atomized multiple droplet carried charges in field.

In order to achieve the above purposes, the technical solution adopted by the utility model is:, and the utility model is a kind of droplet carried charge Measuring device and the measuring device be placed in the underface of range of atomization.The main ring all the same by material, size of measuring device (droplet is arranged in the different insulation droplet box 4 of shape electrode 2, the Teflon insulating materials 3 of the adjacent potential transmitting of isolation, height herein The height of box from top to bottom is d1 > d2 > d3 > d4 ..., and the dimension scale of adjacent insulation droplet box is), CCD television microscope 8 and rack-and-pinion lifting platform 9 form.In order to reduce the number of working voltage source and constitute phase between pairs of annular electrode Same potential difference, replaces connection with the annular electrode in device for the positive and negative electrode of operating voltage.The insulation droplet box of different height It is mounted between paired electrode, supporting role not only is played to electrode, more importantly being protected since droplet box is insulation The mutually indepedent of adjacent electrode potential is demonstrate,proved.It is by field strength formula E=U/d it is found that identical in voltage and insulate droplet box height not With in the case where, gradient distribution electric field is just formd between pairs of annular electrode.Top layer's electrode of the measuring device is by bullet The pressure of spring tabletting 5, holding power of the lowest level electrode by 6 pedestal of hurricane globe, to constitute the flat of entire interelectrode power Weighing apparatus.Due to needing to observe different electric field spaces one by one during measurement, CCD camera is placed in Carry out meet demand on rack-and-pinion lifting platform.

The device is improved the upgrading that original Millikan oil drop instrument carries out.In measurement process, the electric field suffered by the droplet When power is equal or close with gravity, droplet is remain stationary in the electric field region or slow uniform motion.When gravity and electric field force When differing greatly, droplet will be accelerated, until reaching the electric field space to match with droplet gravity.At this point, suffered by droplet Electric field force reach equal or close again with gravity, and then continue to remain stationary or slow uniform motion.

When observing and measuring to droplet, voltage value needed for droplet reaches balance is amount to be asked.And it is filled in the measurement In setting, the value of the electric field force and gravity that are subject to due to the droplet in each electric field space is very close, with regard to balanced voltage Speech only need to do slightly to adjust just being able to satisfy requirement.This also solves the problems, such as that traditional instrument balanced voltage is difficult to adjust in passing.It is logical The relative position of rack-and-pinion lifting platform adjustment CCD camera and camera hole 7 is crossed, to complete to the mist in each electric field space Drip the shooting record of motion profile.Calculating process is consistent with traditional Millikan oil drop instrument method, opens video intercepting software, right Selected droplet carries out observing and measuring for carried charge.

Compared with original Millikan oil drop instrument, the utility model is real by constructing multiple and different electric field strength spaces Under the conditions of having showed primary atomization, to the rapid survey of the droplet carried charge of equivalent amount.Further, since the adjusting of balanced voltage is By successive approximation method, and electric field force suffered by the Charged Droplet in the device and gravity value are close, this just reduces voltage tune Adjusting range reduces voltage and adjusts number.Above description is only the plan explanation of the utility model technology, to allow the utility model Objects, features and advantages be clearer and more comprehensible, hereafter will cooperation attached drawing elaborate.

Detailed description of the invention

Fig. 1 is the constitutional diagram of the utility model measuring device

Fig. 2 is the wiring diagram of utility model works voltage and annular electrode

Fig. 3 is annular electrode and insulating materials partial enlarged view

Figure label explanation: 1. droplet hole, 2. annular electrode, 3. Teflon insulating materials 4. insulation 5. spring pressuring plate of droplet box 6. 7. 10. spring support of camera hole 8.CCD 9. rack-and-pinion lifting platform of video camera of hurricane globe, 11. clamp nut

Specific embodiment

Before formally starting measurement, Charged Droplet is via 1 vertical drop of droplet hole, into droplet box 4.According to electric field force and again The correlation of power, droplet eventually settle in different electric field spaces.It is carried out by position of the lifting platform 9 to CCD camera Adjustment is aligned with camera hole 7, adjusts CCD camera and focuses handwheel, and the Charged Droplet in electric field space is made to concentrate on visual field sight Cha Qu, and it can clearly be observed that droplet and scale.When carrying out observation selection to Charged Droplet, uniform motion should be selected Droplet is as research object.If meeting above-mentioned requirements without droplet, need to can be obtained the slightly adjustment of operating voltage work required Charged Droplet.By video intercepting software in accordance with the order from top to bottom successively to the Charged Droplet in each electric field space Motion profile is recorded.After recording whole, observes the video recorded and record walked path when droplet uniform descent And the time spent.According to the calculating process of traditional Millikan oil drop instrument method, it is sequentially completed selected mist in each electric field space The speed of balanced voltage and droplet uniform descent (is substituted into equilibrium equation: qE=mg by the measurement for dripping carried charge；Mg=F_r, formula Middle F_rFor viscosity resistance, and F_r=6 π μ ν r, μ are known physical quantity.It seeks out droplet radius and then acquires the electrification of selected droplet Amount).

In conclusion the utility model reduces the adjustable range of voltage, saves by constructing different electric field spaces The time required to measurement.Under conditions of primary atomization, the measurement with the droplet carried charge of electric field space number equivalent is realized.

Claims (2)

1. a kind of improvement device based on Millikan oil drop instrument, including droplet separating mechanism, droplet observe and measure mechanism and tooth Take turns rack gear lifting platform 9；It is characterized by: the droplet separating mechanism includes annular electrode 2, Teflon insulating materials 3, constant gradient Insulation droplet box 4, spring pressuring plate 5, the hurricane globe 6 of distribution；The electrode material of the annular electrode 2, size are all the same, and from upper Successively replace connection with the positive and negative electrode of operating voltage under；Described 5 one end of spring pressuring plate is provided with through-hole, and passes through clamp nut 11 are fitted on spring support 10, and the other end compresses the annular electrode of top layer；Lowest level annular electrode is by 6 bottom of hurricane globe The support force of seat；It is mutually isolated by Teflon insulating materials 3 between adjacent annular electrode；By exhausted between pairs of annular electrode Edge droplet box 4 mutually supports；The height of the insulation droplet box 4 of the constant gradient distribution from top to bottom is d1 > d2 > d3 > D4..., and the height ratio of adjacent insulation droplet box is

2. a kind of improvement device based on Millikan oil drop instrument according to claim 1, it is characterised in that: the droplet is seen Examine the monitor that measuring mechanism includes CCD camera and connect with CCD camera；The CCD camera is placed in gear teeth On lifting platform；The relative position of CCD camera and camera hole 7 is adjusted by rack-and-pinion lifting platform 9.