Abstract
A rebreather (1) has at least the following components: a control unit (10), a low pressure system (77) with a breathing bag (3), a low pressure sensor (41), a valve arrangement (7), a hose line system (17), a breathing circuit (15), a mouthpiece (19), a CO2 absorber (13), a high pressure system (79) with a compressed gas supply (5), a pressure reducer (34), and a high pressure sensor (43). The control unit (10) is configured to carry out a procedure for checking the low-pressure system (77).
Claims
1. A process for checking the operational readiness of a rebreather, the process comprising the steps of: continuously metrologically detecting and recording of pressure measurement signals of a low-pressure sensor arranged in or on a low-pressure system of the rebreather; identifying, based on the pressure measurement signals of the low pressure sensor as to whether there is currently a situation in which an inflow of quantities of gas into the low pressure system has started; storing a first pressure measurement signal at a first time, which indicates the identified pressure situation immediately after the start of the inflow of gas quantities into the low-pressure system with a breathing bag; storing a second pressure measurement signal at a second time, which indicates a pressure situation at the end of the inflow of gas quantities into the low-pressure system; forming a differential value between the first pressure signal and the second pressure signal; carrying out a comparison between the difference value and a difference threshold value; determining a result of checking the functionality of the rebreather based on the comparison; and providing an output signal which indicates the result of the check.
2. A process according to claim 1, wherein a first low pressure comparison of the measured values of the low pressure sensor at the first time, with a first lower low pressure threshold value, is carried out.
3. A process according to claim 1, wherein a second low pressure comparison of the measured values of the low pressure sensor at the second time, with a second lower low pressure threshold value, is carried out.
4. A process according to claim 1, wherein a third low pressure comparison of the measured values of the low pressure sensor at a third time, with a third lower low pressure threshold value, is carried out.
5. A process according to claim 1, wherein a continuous, metrological acquisition and recording of pressure measurement signals of a high pressure sensor arranged in or on a high pressure system takes place.
6. A process according to claim 5, wherein a high pressure comparison of measured values of the high pressure sensor at the first time, with a lower high pressure threshold value, is carried out.
7. A process according to claim 6, wherein the high-pressure comparison is performed to determine a pressure level in the high-pressure system or to determine a fluid tightness in the high-pressure system.
8. A process according to claim 1, wherein a computer program with non-transitory computer-readable media or computer program product with non-transitory computer-readable media for carrying out one or more of the process steps.
9. A process according to claim 1, wherein a control unit, comprising a processor and memory, is provided in or on the rebreather to carry out one or more of the process steps.
10. A device comprising: means for continuously metrologically detecting and recording of pressure measurement signals of a low-pressure sensor arranged in or on a low-pressure system of the rebreather; means for identifying, based on the pressure measurement signals of the low pressure sensor as to whether there is currently a situation in which an inflow of quantities of gas into the low pressure system has started; means for storing a first pressure measurement signal at a first time, which indicates the identified pressure situation immediately after the start of the inflow of gas quantities into the low-pressure system with a breathing bag; means for storing a second pressure measurement signal at a second time, which indicates a pressure situation at the end of the inflow of gas quantities into the low-pressure system; means for forming a differential value between the first pressure signal and the second pressure signal; means for carrying out a comparison between the difference value and a difference threshold value; means for determining a result of checking the functionality of the rebreather based on the comparison; and means for providing an output signal which indicates the result of the check.
11. A device according to claim 10, wherein the device is configured as a closed-circuit breathing apparatus, rebreather apparatus or rebreather diving apparatus, which comprises: a control unit configured to provide one or more of said means for continuously metrologically detecting and recording, means for identifying, means for storing a first pressure measurement signal at a first time, means for storing a second pressure measurement signal at a second time, means for forming a differential value, means for carrying out a comparison, means for determining a result of checking, and means for providing an output signal; a low-pressure system comprising a breathing bag, the low-pressure sensor, a valve arrangement, a hose line system, a breathing circuit, a mouthpiece, and a CO.sub.2 absorber; and a high-pressure system comprising a compressed gas supply, a pressure reducer, and the high-pressure sensor.
12. A device according to claim 11, wherein the control unit is configured to provide a first low pressure comparison of the measured values of the low pressure sensor at the first time with a first lower low pressure threshold value.
13. A device according to claim 11, wherein the control unit is configured to provide a second low pressure comparison of the measured values of the low pressure sensor at the second time, with a second lower low pressure threshold value.
14. A device according to claim 11, wherein the control unit is configured to provide a third low pressure comparison of the measured values of the low pressure sensor at a third time, with a third lower low pressure threshold value.
15. A device according to claim 11, wherein the control unit is configured to provide a continuous, metrological acquisition and recording of pressure measurement signals of a high pressure sensor arranged in or on a high pressure system.
16. A device according to claim 15, wherein the control unit is configured to provide a high pressure comparison of measured values of the high pressure sensor at the first time, with a lower high pressure threshold value.
17. A device according to claim 15, wherein the control unit is configured to perform the high-pressure comparison to determine a pressure level in the high-pressure system or to determine a fluid tightness in the high-pressure system.
18. A device according to claim 10, wherein a computer program with non-transitory computer-readable media or computer program product with non-transitory computer-readable media is executable with the control unit for one or more of: continuously metrologically detecting and recording of pressure measurement signals of a low-pressure sensor arranged in or on a low-pressure system of the rebreather; identifying, based on the pressure measurement signals of the low pressure sensor as to whether there is currently a situation in which an inflow of quantities of gas into the low pressure system has started; storing a first pressure measurement signal at a first time, which indicates the identified pressure situation immediately after the start of the inflow of gas quantities into the low-pressure system with a breathing bag; storing a second pressure measurement signal at a second time, which indicates a pressure situation at the end of the inflow of gas quantities into the low-pressure system; forming a differential value between the first pressure signal and the second pressure signal; carrying out a comparison between the difference value and a difference threshold value; determining a result of checking the functionality of the rebreather based on the comparison; providing an output signal which indicates the result of the check.
19. A rebreather device comprising: a low-pressure system comprising a breathing bag, a low-pressure sensor, a valve arrangement, a hose line system, a breathing circuit, a mouthpiece, and a CO.sub.2 absorber; a high-pressure system comprising a compressed gas supply, and a pressure reducer; and a control unit configured to: acquire and record pressure measurement signals of the low-pressure sensor arranged in or on the low-pressure system of the rebreather; identify, based on the pressure measurement signals of the low pressure sensor, whether there is currently a situation in which an inflow of quantities of gas into the low pressure system has started; store a first pressure measurement signal at a first time, which first pressure measurement signal indicates the identified pressure situation immediately after the start of the inflow of gas quantities into the low-pressure system with a breathing bag; store a second pressure measurement signal at a second time, which second pressure measurement signal indicates a pressure situation at the end of the inflow of gas quantities into the low-pressure system; form a differential value between the first pressure signal and the second pressure signal; carry out a comparison between the difference value and a difference threshold value; determine a result of checking functionality of the rebreather based on the comparison; and provide an output signal which indicates the result of the check.
20. A rebreather device according to claim 19, wherein the high-pressure system further comprises a high-pressure sensor arranged in or on a high pressure system and the control unit is further configured to: acquire and record pressure measurement signals of the high pressure sensor; and provide a high pressure comparison of measured values of the high pressure sensor at the first time, with a lower high pressure threshold value, wherein the high-pressure comparison is used to determine a pressure level in the high-pressure system or to determine a fluid tightness in the high-pressure system.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0089] In the drawings:
[0090] FIG. 1 is a schematic diagram of the basic structure of a rebreather;
[0091] FIG. 2 is a schematic diagram of a basic procedure for checking the functional readiness of a rebreather; and
[0092] FIG. 3 is a schematic diagram showing a variant of the process shown in FIG. 2.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0093] Referring to the drawings, FIG. 1 shows a rebreather 1 with a breathing circuit 15, with a control unit 10 for determining gas quantities, with a breathing bag 3, with a compressed gas supply 5, a valve arrangement 7, a CO.sub.2 absorber 13 and an optional breathing gas cooler 12. The rebreather 1 can be connected via a hose line system 17 with an inspiratory branch 21 and an expiratory branch 23 and a mouthpiece 19 to a connection element 24 of a breathing mask 25 of a wearer of the device. The breathing mask 25 is shown here only schematically with connection element 24, a visor 20 and a strap 22. An electronic unit 11 with a control unit 10 and a low-pressure sensor 41 is indicated by a dashed line as an element of the rebreather 1. A high pressure sensor 43 is also assigned to the electronics 11. The electronics 11 also has means for data acquisition (A/D converter), signal amplification and signal filtering. The control unit 10 has a computing unit, for example in the form of a microcontroller (?C) or microprocessor (?P) and an associated data memory (RAM, ROM). A program code can be stored in the data memory (non-transitory and computer readable memory), which can be executed by the control unit 10 in conjunction with electronics 11 and sensors 41, 43 for operation and/or routines for checking functions of the rebreather 1.
[0094] The electronics 11 also has an energy storage unit 87 (battery). In addition, a control and display unit 50 is coupled to the electronics 11 or control unit 10. In the embodiment according to this FIG. 1, elements for operation and display are combined as a control and display unit; embodiments with a separately configured control unit and display unit are also possible within the meaning of the present invention. On the one hand, the control and display unit 50 has means which are suitable for outputting notifications and alarms. These include means for visual or acoustic output, for example for outputting visual representations of notices and/or alarms in the form of single-color or multi-color characters, digits, texts or symbols as suitable display means, as well as acoustic output means, such as horns, loudspeakers or piezo sound elements. On the other hand, the control and display unit 50 also has means for input and operation, such as touch or switching elements. The control and display unit 50 can also be configured as a graphical user interface (UI, GUI). In embodiments according to this FIG. 1, the energy storage unit 87 and the low pressure sensor 41 are shown as part of the electronics 11 by way of example, the high pressure sensor 43 is shown in an embodiment outside the electronics 11, in the sense of the present invention embodiments are also included in which at least one of the two pressure sensors 41, 43 is arranged inside the electronics 11, as well as embodiments in which at least one of the two pressure sensors 41, 43 is arranged outside the electronics 11. In addition, within the meaning (context) of the present invention, the control unit 10 and/or the power supply 87 can be arranged as a whole, predominantly or partially both as components of the electronics 11 and as components of the control and display unit 50. The control and display unit 50 is intended to enable the device wearer to carry out certain operating steps or settings on the rebreather 1, for example for configurations as well as acknowledgements of notifications or alarms, which are generated by the control unit 10 and provided to the control and display unit 50. The rebreather 1 has a construction-shown in this schematic representation according to FIG. 1comprised of a base plate 27 and a spring bridge 29, via which the breathing bag 3 is arranged in the rebreather 1 by means of a spring arrangement 31 and a breathing bag plate 33 in such a way that the gas in the breathing bag 3 is kept at a pressure level above the ambient pressure. The wearer inhales fresh breathing gas via the inspiratory branch 21 of the hose line system 17 from the breathing bag 3 and through the optional breathing gas cooler 12 and via the expiratory branch 23 of the hose line system 17 and via the CO.sub.2 absorber 13 back into the breathing bag 3 and thus into the breathing circuit 15. The valve arrangement 7 has a pressure reducer 34 and a first metering valve 71 as a means of adjusting the pressure from the compressed gas supply 5 to a pressure level that can be breathed by the user 25 for continuous constant metering into the low-pressure system 77, usually in the form of a pulsed metering valve 71, and a second metering valve 71 as a means of adjusting the pressure from the compressed gas supply 5 to a pressure level that can be breathed by the user 25, a second metering valve 72, which can be activated by coupling to deflections of the breathing bag 3 (not shown in this FIG. 1 for reasons of clarity), usually referred to as a minimum valve, for demand-controlled metering, i.e. metering dependent on the depth of respiration, i.e.
[0095] depending on the depth of respiration by the wearer of the device, to feed quantities of breathing gases into the breathing bag 3. A pressure relief valve 75 enables pressure to be released to the environment in the event of excess pressure in the breathing bag 3, which may be possible, for example, in the event of malfunctions at the pressure reducer 34. An optional manual dosing element (bypass element) 18 allows the wearer of the device to directly activate the dosing of gas quantities into the breathing circuit 15, shown in FIG. 1 with an exemplary feed at the breathing gas cooler 12. Other locations for feeding into the breathing circuit 15 or into a low-pressure system 77, for example into the breathing bag 3, are also technically possible. Pneumatic low-pressure lines 73 and a connection block 35 on the pressure reducer 34 pneumatically connect the components 3, 7, 12, 13, 18, 71, 72, 75, 76, 41 to each other and form the low-pressure system 77 with the components. The compressed gas supply 5, configured as a compressed oxygen gas cylinder with a filling pressure of above 200 hPa, forms a high-pressure system 79 with a cylinder valve 74 that can be operated by means of a handwheel 80, high-pressure lines 78 and the pressure reducer 34, the high-pressure sensor 43 and pneumatic high-pressure lines 78. The control unit 10 is connected to the low-pressure sensor 41 and the high-pressure sensor 43 by means of electrical signal lines 81, 83. The control unit 10 is electrically connected to other components of the electronics 11, such as the energy storage unit (battery) 87 and/or the control and display unit 50, by means of electrical connection lines 88. In this FIG. 1, a housing shell 2, in which the components described above are arranged, and a carrying system 28 for transporting the rebreather 1 on the back of a device carrier are shown in use in dashed lines. To check the functionality of the rebreather 1, the mouthpiece 19 of the hose line system 17 can be sealed using a sealing plug 26. In this way, the rebreather 1 can be tested-for example after maintenancewithout pneumatic coupling to the device carrier. For example, leakage tests can be carried out in the high-pressure system 79 or in the low-pressure system 77 with the breathing circuit 15 sealed at the mouthpiece 19.
[0096] FIG. 2 shows in schematic form a basic sequence 100 of a procedure for checking the functional readiness of a rebreather 1 as shown in FIG. 1.
[0097] In order to be able to carry out this functional readiness check with the following sequence 100, the following boundary conditions are required: [0098] The mouthpiece 19 (FIG. 1) on the hose line system 17 (FIG. 1) must be sealed by a sealing plug 26 (FIG. 1). [0099] The low-pressure system 77 (FIG. 1) must be vented; the pressure in the low-pressure system 77 (FIG. 1) therefore corresponds to the ambient pressure.
[0100] The sequence 100 begins with a start 101, the start of the rebreather 1 (FIG. 1) is initiated by a connection 102 of electrical energy 103. With the connection 102 of electrical energy 103, a routine starts in a continuous loop 91 with a continuous data acquisition 104 of measured values P.sub.L of the low pressure sensor 41. At the same time as the data acquisition 104, a low pressure comparison 105 of the measured values P.sub.L 41 with a first lower low pressure threshold value P.sub.A 106 takes place continuously. If the measured value P.sub.L of the low pressure sensor 41 exceeds the lower low pressure threshold value P.sub.A 106, data storage 107 of the measured value P.sub.L 43 as a first low pressure value P.sub.1 109 takes place at a first time t.sub.1 108. In order for the measured value P.sub.L of the low pressure sensor 41 to reach the first lower low pressure threshold value P.sub.A 106, a situation must exist in the rebreather 1 (FIG. 1) in which quantities of breathing gas are currently flowing into the low pressure system 77 (FIG. 1), in particular into the breathing bag 3 (FIG. 1). Such a situation can arise, for example, when the cylinder valve 74 (FIG. 1) is opened. The first low pressure value P.sub.1 109 indicates a pressure level in the low pressure system 77 (FIG. 1) at the start of the rebreather 1 (FIG. 1). The sequence 100 is continued immediately after the low pressure comparison 105 or also during the low pressure comparison 105 with continuous data acquisition 104 of measured values P.sub.L of the low pressure sensor 41. In an optional embodiment of the sequence 100, the continuous data acquisition 104 can be performed limited to a predetermined time duration t.sub.w 92 in a time loop 93. A second low pressure comparison 110 is then carried out during the continuous data acquisition 104 of the measured value P.sub.L of the low pressure sensor 41 with a second lower low pressure threshold value P.sub.B 111. If the measured value P.sub.L of the low pressure sensor 41 exceeds the second lower low pressure threshold value P.sub.B 111, further data storage 112 of the measured value P.sub.L 43 takes place at a second time t.sub.2 113 as a second low pressure value P.sub.2 114. The second low pressure value P.sub.2 114 indicates a pressure level in the low pressure system 77 (FIG. 1) at the end of the filling of the low pressure system 77 (FIG. 1), in particular of the breathing bag 3 (FIG. 1) with a quantity of breathing gas. If the measured value P.sub.L of the low pressure sensor 41 does not exceed the second lower low pressure threshold value P.sub.B 111, a negative check result 94 (fail) is output on a control and display unit 50 (FIG. 1), and the process 100 is terminated 300 (STOP). If the measured value P.sub.L of the low pressure sensor 41 exceeds the second lower low pressure threshold value P.sub.B 111, a difference 115 is formed on the basis of the first low pressure value P.sub.1 109 and the second low pressure value P.sub.2 114 with storage as pressure difference ?P 116. A differential comparison 117 of the pressure difference ?P 116 with a differential threshold value P.sub.C 118 is then carried out. If the pressure difference ?P 116 does not exceed the differential threshold value P.sub.C 118, a negative check result 94 (fail) is output on the control and display unit 50 (FIG. 1). If the pressure difference ?P 116 exceeds the differential threshold value P.sub.C 118, a positive check result 95 (Pass) is output on the control and display unit 50 (FIG. 1). This ends the sequence 100 for checking the functional readiness of a rebreather 1 (FIG. 1) 300 (STOP) and, if the check result 95 is positive, a transition 301 to regular device operation or device provision can take place, or, if the check result 94 is negative, troubleshooting and possibly further checks on the rebreather 1 (FIG. 1) are usually carried out by maintenance personnel until all required check routines with positive results 95, 99 (FIG. 3), 97 (FIG. 3) have been passed.
[0101] FIG. 3 shows in schematic form a variant 200 of the sequence 100 according to FIG. 2 for an extended check of the functional readiness of a rebreather 1 according to FIG. 1. In addition to a check of the low pressure sensor 41, the sequence 200 also includes a check of the high pressure sensor 43. The sequence 200 and the start of the rebreather 1 (FIG. 1) starts in the same way as described for FIG. 2 with the start 201 of the rebreather 1 (FIG. 1) by connecting 102 electrical energy 103. The boundary conditions mentioned for FIG. 2 must also be given in the same way as described for FIG. 2 in order to be able to carry out the alternative sequence 200 for an extended check of the functional readiness. After the first data acquisition 104 of the low pressure sensor P.sub.L 41 and the subsequent first low pressure comparison 105 with the first low pressure threshold value 106 as described for FIG. 2, a check of the high pressure system 79 (FIG. 1) is performed in addition to the check of the low pressure system 77 (FIG. 1). For this purpose, a continuous data acquisition 204 of measured values P.sub.H of the high pressure sensor 43 (FIG. 1) takes place in a time loop 93 for a predetermined period of time 92. After the predetermined period of time 92 has elapsed, a check of the low pressure system 77 (FIG. 1) takes place as in the sequence 100 with the action elements 107, 104, 112, 115, 300, comparison elements 110, 117 with threshold values 111, 118, data storage 108, 109, 113, 114, 116 and an output of the check results 94, 95. In addition, a high pressure comparison 220 of a measured value P of the high pressure sensor 43 recorded at the end of the predetermined time period 92 with a high pressure threshold value 219 is performed. If the measured value P.sub.H of the high pressure sensor 43 does not exceed the lower high pressure threshold value P.sub.D, a negative check result 96 (fail) is output on a control and display unit 50 (FIG. 1). If the measured value P.sub.H of the high pressure sensor 43 exceeds the lower high pressure threshold value P.sub.D, a positive check result 97 (Pass) is output on a control and display unit 50 (FIG. 1). In this FIG. 3, a type of provision 93 of the check results 93, 94, 95, 96, 97, 98, 99 is shown as an example, schematically and symbolically, as it can be realized on a control and display unit 50 (FIG. 1) with graphic output options. In this FIG. 3, a check of the energy supply, for example of a battery charge state directly after the start 201 of the sequence 200, is shown as an example of further checks; in this exemplary embodiment, the check results 98, 99 are then fed to the provision 93, for example as the situation of a battery storage unit 87 (FIG. 1) with a good charge state 99 or a charge state 98 that is too low. The steps following the provision 93 in this FIG. 3 can also be configured, for example, as described for FIG. 2 with a termination 300 (FIG. 2) of the process 100 (FIG. 1) or the process 200. In this FIG. 3for reasons of clarity of the drawing of FIG. 3only a transition 301 is indicated, which can be configured as a transition 301 to a regular device operation, to a device provision or as a transition to further tests. Interactions with a user, for example details of the electrical start-up 102, 103 of the rebreather 1 (FIG. 1) or opening or closing of the cylinder valve 74 (FIG. 1) by means of a handwheel 80 (FIG. 1) in the course of the sequence 200 of checking the low-pressure system 79 (FIG. 1), any actuations or acknowledgements of the user on the display and control unit 50 (UI, GUI) (FIG. 1) required in the sequence 200 are not shown in FIG. 3 for reasons of clarity of the drawings.
[0102] While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.
REFERENCE NUMBER LIST
[0103] 1 Circulatory breathing apparatus, rebreather apparatus, rebreather diver [0104] 2 Housing shell (case) [0105] 3 Breathing bag, counterlung [0106] 5 Compressed gas supply, compressed oxygen gas cylinder [0107] 7 Valve arrangement [0108] 10 Control unit [0109] 11 Electronics, electronics module [0110] 12 Breathing gas cooler [0111] 13 CO.sub.2absorber, breathing soda lime container [0112] 15 Breathing circuit (breathing circuit in the low pressure system) [0113] 16 Control element (button) for bypass element [0114] 17 Hose line system (inhalation and exhalation hose) [0115] 18 Manual dosing element, bypass element (O.sub.2additional dosing) [0116] 19 Mouthpiece on the hose line system [0117] 20 Visor of the breathing mask [0118] 21 Inspiratory branch (inhalation tube) [0119] 22 Strapping of the breathing mask [0120] 23 Expiratory branch (exhalation tube) [0121] 24 Connection element on the breathing mask [0122] 25 Respirator mask, user [0123] 26 Sealing plug for mouthpiece on the hose line system [0124] 27 Base plate [0125] 28 Carrying system (straps, belt system) [0126] 29 Spring bridge arrangement (base plate, spring arrangement) [0127] 31 Spring arrangement, spring assembly [0128] 33 Breathing bag plate [0129] 34 Pressure reducer (device for reducing pressure) [0130] 35 Connection block/manifold (low-pressure distribution) [0131] 41 Low pressure sensor P.sub.L [0132] 43 High pressure sensor P.sub.H [0133] 50 Display and control unit (UI, GUI) [0134] 71 First dosing valve (constant dosing) [0135] 72 Second dosing valve, minimum valve (on-demand dosing) [0136] 73 Low-pressure lines/tubes/pipes in the low-pressure system [0137] 74 Gas-cylinder valve (shut-off valve) [0138] 75 Pressure relief valve (relief valve) [0139] 76 Pneumatic connecting elements (plug/coupling) [0140] 77 Low pressure system [0141] 78 High-pressure lines/tubes/pipes in the high-pressure system [0142] 79 High pressure system [0143] 80 Handwheel (rotary wheel) [0144] 81 Electrical signal line (low pressure sensor) [0145] 83 Electrical signal line (high pressure sensor) [0146] 87 Energy storage (battery) [0147] 88 Electrical connecting cables [0148] 91 Continuous loop [0149] 92 Predetermined time period tw [0150] 93 Time loop [0151] 93 Provision of test results, output or presentation [0152] 94 Negative check result Low pressure check [0153] 95 Positive check result Low pressure check [0154] 96 Negative check result High pressure check [0155] 97 Positive check result High pressure check [0156] 98 Negative result energy supply check (charge level low) [0157] 99 Positive result energy supply check (state of charge good) [0158] 100 Sequence (FIG. 2, FIG. 3) of the check (test) [0159] 101 Start (start of the low pressure check) [0160] 102 Connection (switch-on), switch actuation [0161] 103 Electrical energy, energy storage (battery) [0162] 104, 104 Data acquisition P.sub.L, low pressure [0163] 105 First low-pressure comparison, comparison [0164] 106 First lower low-pressure threshold P.sub.A [0165] 107 Data storage Low pressure P.sub.1 [0166] 108 First time t.sub.1 [0167] 109 First low pressure value P.sub.1 [0168] 110 Second low-pressure comparison, comparison [0169] 111 Second lower low-pressure threshold P.sub.B [0170] 112 Data storage low pressure P.sub.2 [0171] 113 Second time t.sub.2 [0172] 114 First low pressure value P.sub.1 [0173] 115 Differential formation low pressure [0174] 116 Pressure difference low pressure ?P [0175] 117 Differential comparison low pressure [0176] 118 Differential threshold value low pressure P.sub.C [0177] 200 Alternative test procedure (FIG. 3) [0178] 201 Start (start of the combined low-pressure/high-pressure check) [0179] 202 Checking the power supply (battery charge status) [0180] 204 Data acquisition PH, high pressure [0181] 219 Lower high pressure threshold P.sub.D [0182] 220 High pressure comparison, comparison [0183] 300 STOP (end of check) [0184] 301 Transition
