| 摘要 |
<p>PURPOSE:To eliminate the overflow of a low-temp. fluid by providing a level gage to output the detection signal of the liq. level of the low-temp. fluid in a trap and a controller for operating and stopping a low-temp. fluid supply means on the basis of the detection signal from the level gage. CONSTITUTION:The voltage value corresponding to the upper limit level H of the liq. level and the voltage value corresponding to the lower limit level L are previously given to the liq. supplying and stopping device 18. When the liq. level is raised to the upper limit level H, a valve closing command is outputted from the liq. supplying and stopping device 18 to a pressure valve 11. Simultaneously, when the liq. level is lowered to the lower limit position L, a valve opening command is outputted from the liq. supplying and stopping device 18 to the pressure valve 11. As the valve 11 is thus opened and closed, the supply of liquefied nitrogen to the trap 3 and the stoppage of the supply are automatically controlled. Accordingly, the overflow of the liquefied nitrogen 7 from the trap 3 is eliminated.</p> |
