Device for the measurement of liquid level

A machine for determining the distance from the bottom of a storage tank to the liquid-vapor interface of a liquid stored therein comprising:

• a liquid vapor interface probe, said probe including a pair of electrically actuated medium sensing elements having an output;
• a cable within said storage tank, said cable having said probe connected adjacent one end thereto;
• pulse actuated stepping motor, said cable connected to said motor for lifting and lowering said cable and said probe placed within said storage tank;
• a motor direction and speed control means connected to said motor and the output of said liquid vapor interface sensing elements;
• liquid depth measurement display means for providing distance data connected to said motor control means;
• a probe drive means connected to said motor and said cable, said probe drive means connected to said motor control means and said display means;
• pulse counting means connected to said motor control means and said display means
• a pair of guide wires connected to said probe;
• a weight coupled to the end of said guide wires, said weight having a probe receiving aperture disposed therethrough;
• and
• a tension switch connected to said cable and said probe drive means for providing a signal indicative of said probe contacting the bottom of the tank for calibration purposes.

A machine for determining the distance from the bottom of a storage tank to the liquid-vapor interface of a liquid stored therein comprising:

• a liquid vapor interface probe, said probe including a pair of electrically actuated medium sensing elements having an output;
• a cable within said storage tank, said cable having said probe connected adjacent one end thereto;
• pulse actuated stepping motor, said cable connected to said motor for lifting and lowering said cable and said probe placed within said storage tank;
• a motor direction and speed control means connected to said motor and the output of said liquid vapor interface sensing elements;
• liquid depth measurement display means for providing distance data connected to said motor control means,
• a probe drive means connected to said motor and said cable,
• said probe drive means connected to said motor control means and said display means;
• pulse counting means connected to said motor control means and said display means,
• said medium sensing elements have a variable electrical resistance dependent upon heat dissipation of the elements;
• a first level detecting circuit means connected to a first sensing element;
• second level detecting circuit connected to a second sensing element;
• a counting and gating logic means connected to the output of said first and second level detecting circuit means;
• said motor control means including motor driver circuit means connected to said motor and said counter and gating logic means;
• said pulse counting means connected to said counter and gating logic means,
• said motor control means including a speed control means connected to said motor driver and said counter engaging logic means;
• motor direction control means connected to said first and second level detection circuit means.

A device for measuring the liquid level in a closed storage tank comprising:

• a pair of thermally responsive heat sensing elements, said elements disposed vertically relative to each other forming an upper sensing element and a lower sensing element;
• an electrical power source;
• a cable disposable within a storage tank, said cable having said upper and lower sensing probes connected thereto at one end;
• a probe-cable stabilizing means connected within a storage tank to said probe;
• a display means for displaying the depth of the liquid in measurable units;
• a motor control circuit means connected to said power source to said motor and to said sensing probes;
• pulse counting means connected to said control circuit means;
• a means connected to said sensing probes for providing a signal when said upper probe is disposed in a vapor environment and said lower sensing probe is disposed in a liquid environment;
• motor control means connected for incrementally driving said motor in steps as a function of a plurality of pulses;
• means connected for controlling said motor to drive said probe to the bottom of the tank simultaneously provide a zero reference point for said counting control means;
• and
• means connected for driving said probe upward from the bottom of said tank until said upper sensor is in a vapor environment and said lower sensor is in a liquid environment indicative of the liquid level interface;
• and
• a means for counting the incremental steps of said motor to determine the distance from the bottom of the tank to the liquid level interface at the probe position.

A device for detecting and measuring in a visual remote display the liquid level in a closed liquid storage tank comprising:

• a cable, said cable having a helical gear tooth surface coupled about its periphery;
• a vapor liquid interface probe connected at one end of said cable, said probe including an upper sensing element and vertically disposed below, a lower sensing element, said upper sensing element and said lower sensing element having a variable electrical resistance as a function of heat dissipation;
• a first level detection circuit means connected to said upper sensing element;
• a second level detection circuit means connected to said lower sensing element;
• a pulse actuated stepping motor, said motor being moveable in a first direction or a second opposite direction;
• a means for connecting said cable to said motor whereby said motor may move said cable vertically upwardly or downwardly;
• a motor direction and speed control circuit means connected to said first and second level detection circuit means and said motor;
• liquid level measurement display means;
• motor direction and control circuit means connected to said first and second level detection circuits in said motor;
• pulse counting means connected to said motor direction and speed control circuit means;
• and
• means for sealably connecting said cable and said motor within the same vapor atmosphere as in the storage tank.

A device mountable on a storage tank for storing liquid gas, said device including a remote distance measuring display device providing a distance from the bottom of a storage tank to the liquid vapor interface comprising:

• probe means for detecting a liquid vapor interface;
• means for positioning said probe means vertically within the storage tank to a position about the liquid vapor interface, said means for positioning connected to said probe means;
• means for moving said probe means fron a first position at the bottom of said tank to a second position at the liquid vapor interface said means for moving connected to said means for positioning;
• means for generating a signal continuously indicative of the distance moved by said probe means from said first position at the bottom of said tank to said liquid vapor interface, said means for generating a signal connected to said means for moving;
• and
• means connected to said means for generating a signal for displaying indicia representing the distance between the bottom of said tank and the probe means;
• and
• a bottom sensing system connected to said means for sensing the bottom of said storage tank, said sensing system connected to said means for moving and said means for displaying.

A machine for determining the position of the liquid-vapor interface in a storage tank comprising:

• a movable liquid-vapor interface probe in the storage tank, said probe including at least one electrically actuated medium sensing element, said medium sensing element having a variable electrical resistance dependent upon each dissipation of the element;
• a drive means including a cable, a motor means, and a motor control means;
• said cable at least partially extending into said storage tank, said cable connected to said probe;
• said motor means connected to said cable for lifting and lowering said cable and said probe within said storage tank, said motor means connected to a measurement signal means to provide at least one liquid-vapor interface position signal;
• said motor control means connected to said motor and said liquid-vapor interface probe;
• said measuring signal means connected to said motor control means for providing at least one liquid-vapor interface position signal;
• and
• a sensing means for sensing the bottom of the tank connected to said drive means and said measuring signal means.