電振音叉說明書J-SB2型

User’s Manual for J-SB2 Fork Oscillator

用途：

Application:

供大專學校基礎物理實驗，作邁爾德氏弦振動試驗之用。

Specially used for Maier De's string vibration test in fundamental physics experiment of universities and colleges

結構及基本性能：

Structure and basic properties:

       本儀器為一大型音叉，由整塊的鋼材切削而成。在兩叉枝的頂端，裝置記錄筆尖一對，以供記錄波紋之用。叉柄固著于木質底板上的Ω型底坐上，在兩叉枝間距叉頂約三分之一處，裝置一電磁鐵，在左側叉枝的外側配備斷續接觸器，接通電流后，配合音叉的振動，形成勵磁線圈斷續通電，致使電磁鐵產生間斷吸力，驅使音叉作長期的振動。本音叉頻率約為100周/秒，每具音叉的實際頻率數均用硬印標出。標出的頻率數據就是是音叉頂部裝有一對記錄筆尖的頻率，如將此等附件連同螺絲全部卸去，則頻率約增加4分之3周。由于音叉叉枝質量較大，故在實驗中如弦振動駐波試驗等，負荷稍有變動時，對頻率的影響不大。

This instrument is a large tuning fork made from the cutting of one-piece steel material. A pair of recording pen-points is mounted at the top of two branches for the purpose of recording ripples. Fork handle is fixed on the Ω type seat of wooden bottom plate, one electromagnet is arranged between two fork branches and about one third away from the fork top, and an intermittent contactor is mounted at the outside of left-side fork branch. After the power supply is switched on, it is possible to form excitation coil, provide intermittent electricity, cause the electromagnet to produce intermittent suction, and drive the tuning form to produce long-term vibration. The frequency of tuning fork is 100 cycle per second, and the actual frequency number of each of tuning fork is marked with embossing seal. The marked frequency data equals to the frequency of a pair of recording pen points mounted at the top of tuning fork, and the frequency may increase 3/4 cycle, provided that these accessories and other screws are compley dismantled. Due to the larger mass of tuning form branch, slight changes in load may not have significant impact on frequency in such experiment as string vibration standing wave test.

使用方法：

Use Method:

       將本儀器底板上所附電源輸出叉頭接在底板的接線柱上（或根據需要另接電源），調節斷續器接觸點螺絲，使音叉維持穩定振動，叉端振幅約達1.5m/m。調節適度后，即將螺帽固緊使不至松動。一次調節后如所用電源的電壓不變，則以后使用時可不必再行調節。在使用時如音叉呈靜止狀態,則斷續器不能起正常的作用。故在接通電流時，可輕敲叉枝，協助音叉起動。

   Connect the power output plug (attached on the bottom plate of this instrument) onto the terminal of bottom plate (or otherwise connect to power as required), regulate the contact point screw of interrupter to enable the tuning fork to maintain steady vibration, and the fork-side amplitude may reach 1.5m/m. After an appropriate adjustment, it is necessary to tighten the screwed cap and avoid looseness. Readjustments are not required in the later uses, provided that the voltage of power supply remains unchanged after the first time of adjustment. The interrupter can not play a normal role if the tuning fork is in resting state during application. Therefore, it is possible to gently strike the fork branch to help the start of tuning fork when the current is switched.

       本音叉叉枝的頂端有螺絲，作邁爾德氏弦振動試驗時，可將弦線一端用螺絲固著。

    Screw is mounted at the top of tuning fork branch, and it is possible to fix one end of string with screw when Maier De's string vibration test is being conducted.

儀器的保管：

Storage of Instrument:

       音叉的叉枝上如發生銹蝕等變化或附著厚層油污，能直接影響音叉的頻率，故在使用之前，須以柔軟紗布將油污楷試潔凈，在使用完畢之后，須遍涂防銹油，音叉須放置于干燥處，以防銹蝕。

The frequency of tuning fork may be directly affected if erosion and other changes exist in the fork branch of tuning fork, or the branch is covered with thick oil stain. For this regard, it is necessary to use soft gauze to wipe off the oil stain before the application of this instrument. Moreover, it is also necessary to coat anti-rust oil throughout the instrument after the completion of application. The tuning fork must be stored at dry place to avoid corrosion.

重量：…………………………………………………………………………………….約3.5公斤

Weight: ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ..  About 3.5 kg

外形尺寸:………………………………………………………………….音叉叉枝長約300毫米

Dimension:                       Length of tuning fork branch is about 300mm

                                                           厚約       8毫米

                                                           Thickness    8 mm

                                                           寬約     23毫米

                                                           Width    23 mm

                                                           木底板  160x395毫米

                                                  Wooden bottom plate 160x395 mm