MEASURING DEVICE AND ASSOCIATED OPERATING METHOD

Abstract

In order to prolong maintenance-free and autonomous operation of an electrical measuring device (1) having an internal energy store (4) and measuring electronics (3) for reading a sensor (2), wherein the latter is configured for detecting an ambient variable such as, for instance, a room temperature or room humidity, it is provided that as needed, in a manner dependent on an ambient temperature detected by the measuring device (1), a buffer capacitor (5) is electrically connected to the energy store (4) such that the buffer capacitor (5) can draw electrical power from the energy store (4) and can make this power available again, in particular in the event of a dip in an electrical operating voltage of the measuring device (1), in order thus to buffer current peaks of a load current of the measuring electronics (3).

Claims

1. A measuring device (1), comprising: a sensor (2) for detecting an ambient variable; measuring electronics (3) configured for reading the sensor (2) and for acquiring measurement values of the sensor (2), said measuring electronics being supplied with electrical operating voltage by an electrical energy store (4); and a buffer capacitor (5) that is chargeable by the energy store (4) and is arranged to supply an electric current to the measuring electronics (3) in addition to the energy store (4), and is configured to be connected and disconnected.

2. The measuring device (1) as claimed in claim 1, wherein the ambient variable is a room temperature or room humidity.

3. The measuring device (1) as claimed in claim 1, wherein the connecting of the buffer capacitor (5) is dependent upon a detected ambient temperature.

4. The measuring device (1) as claimed in claim 1, wherein the sensor is a temperature sensor (6), and the measuring device (1) is configured to detect an ambient temperature continuously or at regular intervals with the temperature sensor (6) and to electrically connect the buffer capacitor (5) as soon as the detected ambient temperature falls below a limit temperature, and to electrically disconnect the buffer capacitor (5) if the detected ambient temperature exceeds the limit temperature again.

5. The measuring device (1) as claimed in claim 1, wherein the measurement electronics is configured with a comparison logic which causes the buffer capacitor (5) to be connected in the event of a first temperature threshold value being undershot and causes the buffer capacitor (5) to be electrically isolated in the event of a second temperature threshold value being exceeded.

6. The measuring device (1) as claimed in claim 5, further comprising an electrical switch that is driven by the comparison logic in the measurement electronics that electrically connects the buffer capacitor (5) to at least one of the energy store (4) or the measuring electronics (3).

7. The measuring device (1) as claimed in claim 1, wherein the electrical energy store (4) comprises a non-rechargeable electrochemical energy store or a rechargeable electrical battery.

8. The measuring device (1) as claimed in claim 1, wherein the buffer capacitor (5), in relation to the measuring electronics (3), is electrically connected in parallel with the electrical energy store (4).

9. The measuring device (1) as claimed claim 1, wherein the measuring device (1) is configured for automatic recurring capture of measurement values using the sensor (2) according to a time schedule.

10. The measuring device (1) as claimed in claim 1, wherein the measuring device (1) is configured acquire and record measurement values continuously using the sensor (2) and the electrical energy store (4) autonomously with respect to other energy sources.

11. The measuring device (1) as claimed in claim 1, wherein the measuring device (1) is at least one of a portable handheld measuring device or an energy-autonomous measuring device (1).

12. A method for temperature-optimized operation of a measuring device (1), the method comprising: providing the measuring device (1) which includes a sensor (2) for detecting an ambient variable, measuring electronics (3) configured for reading the sensor (2) and for acquiring measurement values of the sensor (2), said measuring electronics being supplied with electrical operating voltage by an electrical energy store (4), and a buffer capacitor (5); independently and continuously detecting an ambient temperature using the measuring device (1); and the measuring device electrically connecting the buffer capacitor (5) dependent on the detected ambient temperature dropping below a limit temperature such that the buffer capacitor (5) draws electrical power from the internal electrical energy store (4) as needed, and the buffer capacitor (5) supplying electrical power as necessary to the measuring electronics (3) for operation thereof.

13. The method of claim 12, wherein the limit temperature is ambient temperatures below 0° C.

14. The method as claimed claim 12, further comprising the measuring device (1) disconnecting the buffer capacitor (5) if a further limit temperature is exceeded such that no electric current flow whatsoever from the energy store (4) into the buffer capacitor (5) is possible.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The invention will now be described in greater detail on the basis of an exemplary embodiment, but is not restricted to this example. Rather, further embodiments of the invention can be gathered from the following description in conjunction with the general description, the claims and the drawings.

[0028] Here:

[0029] FIG. 1: shows a schematic, greatly simplified, illustration of a measuring device according to the invention.

DETAILED DESCRIPTION

[0030] The sole FIG. 1 shows a schematic diagram of the electrical components of a measuring device 1 according to the invention. The measuring device 1 comprises a sensor 2 for detecting an ambient variable such as, for instance, the room humidity and an associated measuring electronics 3, for example including a controller, configured for reading the sensor 2 and for acquiring measurement values of the sensor 2.

[0031] The measuring device 1 in FIG. 1 is designed as a data logger and for this purpose is configured, automatically at recurring time intervals, to capture measurement values with the aid of a sensor 2 and to store these measurement values in an internal memory. Due to the electrical operating voltage that can be made available by the electrical energy store 4, the measuring device 1 can thus be operated autonomously with respect to other energy sources in order thus to continuously acquire and record measurement values using the sensor 2.

[0032] As is illustrated on the basis of the electrical connections in FIG. 1, an electrical operating voltage is fed to the measuring electronics 3 by an electrical energy store 4. A switching arrangement comprising a buffer capacitor 5 and an electrical switching means 7 connected in series therewith is connected in parallel with the two connection terminals 8 of the measuring electronics 3, via which the latter is electrically connected to the energy store 4. The electrical switching means 7 is illustrated as an electrical switch in FIG. 1 and can be realized for example with a semiconductor component or a relay.

[0033] Since the switching arrangement comprising buffer capacitor 5 and switching means 7 is also electrically connected to the energy store 4, the buffer capacitor 5 can be charged by means of the energy store 4 when the switching means 7 is correspondingly switched, i.e. the switch 7 is closed. In this switching state, that is to say when both poles of the buffer capacitor 5 are electrically connected to the two terminals of the measuring electronics 3, the buffer capacitor 5 can supply an electric (discharge) current to the measuring electronics 3 in addition to the energy store 4 and can thus stabilize the operating voltage dropped across the two terminals 8 of the measuring electronics 3.

[0034] In other words, the buffer capacitor 5 (provided that it was electrically charged from the energy store 4 to a sufficient extent beforehand) can discharge into the two terminals 8 of the measuring electronics 3 as soon as the switching means 7 electrically connects the buffer capacitor 5. If necessary, however, by way of the opening of the switch 7, that is to say by way of renewed switching of the switching means 7, it is also possible if necessary for the buffer capacitor 5 to be disconnected, i.e. electrically isolated from the measuring electronics 3. By means of such electrical disconnection of the buffer capacitor 5, the latter can thus be electrically decoupled from the measuring electronics 3 and the energy store 4, with the result that although on the one hand the buffer capacitor 5 can no longer supply current to the measuring electronics 3, on the other hand it can also no longer draw current from the energy store 4. Such a procedure can be advantageous in order to avoid an energy consumption on account of shunt currents in the capacitor (leakage currents), since such shunt currents can unnecessarily load the energy store 4, in particular if the additional current flow supplied by the capacitor 5 is not required at present, for instance because there is no occurrence of relatively large current peaks in the current consumption of the measuring electronics 3.

[0035] In order that connecting and disconnecting the buffer capacitor 5 can proceed intelligently and automatically, the measuring electronics 3 continuously measures the ambient temperature with the aid of an additional temperature sensor 6. If the ambient temperature thus detected falls below a predefined limit temperature, then the measuring electronics 3 connects the buffer capacitor 5 by virtue of the fact that, for this purpose, said measuring electronics drives the switching means 7 in a suitable manner, as is illustrated by the dotted arrow in FIG. 1. That is to say that at low temperatures at which current peaks may typically occur, the buffer capacitor 5 is available for buffering these current peaks (which occur in the consumption by the measuring electronics 3).

[0036] As soon as the ambient temperature detected by the measuring electronics 3 with the aid of the temperature sensor 6 rises above the aforementioned limit temperature again, the measuring electronics 3 disconnects the buffer capacitor 5 by way of corresponding renewed driving of the switching means 7 and thus interrupts the electrical connection between the buffer capacitor 5 and the measuring electronics 3. In this case, the limit temperature is chosen such that in the temperature range above the limit temperature, the measuring electronics 3 is able to be supplied with electric current by the energy store 4 to a sufficient extent. As a result of the disconnection of the buffer capacitor 5 at warmer temperatures, the entire current consumption of the measuring device 1, which after all can be drawn exclusively from the energy store 4 (since the capacitor 5 can only buffer-store electrical energy from the energy store 4), is thus reduced, thus giving rise to a longer lifetime or operational period of the measuring device 1.

[0037] It is easily conceivable with reference to FIG. 1 that, provided that for example the lower connecting terminal 8 of the measuring electronics 3 is grounded, the buffer capacitor 5 shares a common electrical ground with the energy store 4.

[0038] The measuring device 1 shown in FIG. 1 thus also implements a method according to the invention for the temperature-optimized operation of the measuring device 1. This is because the measuring device 1 independently and continuously detects the ambient temperature with the aid of the separate temperature sensor 6 and, in a manner dependent on this detected ambient temperature, as was explained above, electrically connects and disconnects the buffer capacitor 5 by way of the driving of the corresponding switching means 7. As a result, as needed, namely as soon as the detected ambient temperature falls below the aforementioned threshold value, the buffer capacitor 5 is electrically connected to the terminals 8 of the measuring electronics 3 and in this case can firstly draw electrical power from the internal electrical energy store 4 (charging process of the capacitor 5) in order subsequently—as necessary—to feed the electrical energy buffer-stored in this way in the form of a discharge current (discharging process of the capacitor 5) into the switching arrangement shown in FIG. 1 and thus to make it available to the measuring electronics 3 for the operation thereof.

[0039] In summary, in order to prolong maintenance-free and autonomous operation of an electrical measuring device 1 having an internal energy store 4 and measuring electronics 3 for reading a sensor 2, wherein the latter is configured for detecting an ambient variable such as, for instance, a room temperature or room humidity, it is proposed that as needed, in a manner dependent on an ambient temperature detected by the measuring device 1, a buffer capacitor 5 is electrically connected to the energy store 4 with the aid of a suitable switching means 7 in such a way that the buffer capacitor 5 can draw electrical power from the energy store 4 and can make this power available again, in particular in the event of a dip in an electrical operating voltage of the measuring device 1, in order thus to buffer current peaks of a load current of the measuring electronics 3 (cf. FIG. 1).

LIST OF REFERENCE SIGNS

[0040] 1 Measuring device [0041] 2 Sensor [0042] 3 Measuring electronics [0043] 4 Energy store [0044] 5 Buffer capacitor [0045] 6 Temperature sensor [0046] 7 Switching means [0047] 8 Connecting terminal (of 3)