SYSTEM FOR MEASURING A PHYSICAL VARIABLE

• US 20100071459A1
• Filed: 10/30/2007
• Published: 03/25/2010
• Est. Priority Date: 12/01/2006
• Status: Active Grant

• Current Assignee: Tecan Trading AG (Tecan Group AG)
• Original Assignee: Tecan Trading AG (Tecan Group AG)
• Inventors: Kamm, Lars, Baumann, Roman, Hinn, Werner
• Granted Patent: US 8,353,210 B2
• Time in Patent Office: Days
• US Class Current: 73/304.C
• CPC Class Codes: G01D 3/036 on measuring arrangements themselves
• CPC Class Codes: G01D 5/24 by varying capacitance
• CPC Class Codes: G01L 1/144 with associated circuitry G01L1/146 and G01L1/148 take precedence
• CPC Class Codes: G01L 1/146 for measuring force distributions, e.g. using force arrays G01L1/148 takes precedence
• CPC Class Codes: G01R 27/2605 Measuring capacitance capacitive sensors G01D5/24
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/044 by capacitive means

Abstract

The invention relates to a system for measuring a physical variable using a plurality of measuring sensors (20). Said system is characterized in that an inverting measuring signal amplifier (17; 17.1, 17.2) is connected downstream of every measuring sensor (20), one output of a sensor (20) each being connected to an inverting input of the measuring signal amplifier (17; 17.1, 17.2) connected downstream of the measuring sensor (20).

Claims

1. System for measuring a physical value, in particular for measuring a fill level, having multiple measuring sensors (20), characterized in that capacitive sensors (20) serve as said measuring sensors (20), that an inverting measuring signal amplifier (17;

17.1, 17.2) is connected downstream from each measuring sensor (20), one output of a measuring sensor (20) being connected to an inverting input of the inverting measuring signal amplifier (17;

17.1, 17.2) connected downstream from the measuring sensor (20) in each case, and said capacitive sensors (20) are formed by a transmitter electrode (S) and multiple receiver electrodes (E;

E1, E2, E3, E4), the receiver electrodes (E;

E1, E2, E3, E4) being situated spaced apart from the transmitter electrode

3. System according to claim 1, characterized in that the receiver electrodes (E;

E1, E2, E3, E4) are situated in a spatial plane and no shielding is provided in the spatial plane between the receiver electrodes (E;

E1, E2, E3, E4).

4. System according to claim 1, characterized in that an integrator (19;

23) is connected downstream from each inverting measuring signal amplifier (17;

17.1, 17.2), to whose inverting input an output signal of the inverting measuring signal amplifier (17;

17.1, 17.2) is applied.

5. System according to claim 1, characterized in that a reference signal generator (21) is associated with each measuring sensor (20), to which an inverting reference signal amplifier (22) is connected downstream, an output of the reference signal generator (21) being connected to an inverting input of the inverting reference signal amplifier (22).

6. System according to claim 5, characterized in that an integrator (23) is connected downstream from each inverting measuring signal amplifier (17;

17.1, 17.2), to whose inverting input an output signal of the inverting measuring signal amplifier (17;

17.1, 17.2) is applied and to whose non-inverting input an output signal of the inverting reference signal amplifier (22) is applied, to which the reference signal generator (21) is connected downstream, with which the measuring sensor (20) is associated, to which the inverting measuring signal amplifier (17;

17.1, 17.2) is connected downstream.

7. System according to claim 6, characterized in that an integrator (25) is connected downstream from the inverting reference signal amplifier (22), to whose inverting input an output signal of the inverting reference signal amplifier (22) is applied.

8. System according to claim 7, characterized in that an output signal of the inverting measuring signal amplifier (17;

17.1, 17.2), to which the measuring sensor (20) is connected downstream, with which the reference signal generator (21) is associated, to which the inverting reference signal amplifier (22) is connected downstream, is applied to the non-inverting input of the integrator (25) downstream from the inverting reference signal amplifier (22).

9. System according to claim 1, characterized in that the inverting measuring signal amplifier (17;

17.1, 17.2) and/or the inverting reference signal amplifier (22) are each implemented as a high-pass filter.

10. System according to claim 1, characterized in that it is designed for measuring a fill level.

2. (canceled)