Automatic calibration of instrument timers

Abstract

The invention relates to a system for calibrating a timer, comprising a device (1) comprising a timer (10) wherein the device (1) is configured to perform analysis using the timer (10) and the device (1) is configured to calibrate the timer (10) of the device (1) based on a reference time interval TR expired on a timer (20) of an NTP server (2).

Description

Technical Field

[0001] The present invention relates to a system and method for calibrating a device timer. Background Art

[0002] In many devices that analyze substances, the duration of the analysis affects the results. This is particularly true in the areas of particle collection and sampling, as well as the analysis of various particles. Precise knowledge of the analysis interval is crucial when using fluid characterization equipment, such as for gas or air quality, as required in the food and beverage industry, or in clean environments such as cleanrooms and manufacturing environments. An example of such a clean environment is production lines in the pharmaceutical industry, where air quality must be continuously monitored and tested.

[0003] A microbial air sampler is a specific type of air monitoring device that focuses on the collection of particles—usually on a microbial growth medium in the form of a petri dish containing an agar medium or similar, or on a carrier (such as a filter) from which the collected particles can be transferred to the growth medium. After the particles are collected from the gas / air on such a plate, the plate is incubated for several hours or even days to allow the collected viable microorganisms to grow into visible colonies for subsequent counting and analysis.

[0004] Often, there are regulatory limits on the number and types of organisms that can be tolerated in a particular environment, and production batches of, for example, a pharmaceutical product are typically discarded if these limits are exceeded.

[0005] Air quality analysis focusing on microbial contamination is therefore a key quality indicator for product release in several large industries. Consequently, equipment used in this field must quantify microbial contamination and gas volumes with the highest possible precision. Relying on subjectively accurate equipment is often insufficient; its accuracy must be objectively demonstrated by comparing each relevant measurement of the equipment to a reference (a process also known as "calibration" or "calibration"). For such calibration to be valid, the validity of the reference must be demonstrated through an unbroken chain of calibrations that are traceable back to national calibration standards maintained by (national) metrology institutes (traceable calibration).

[0006] In the context of quantifying microbial contamination, it is often of particular interest to quantify the mass or volume of a sample, which corresponds to the mass or volume flow rate integrated over time.

[0007] While (subjectively) highly accurate timepieces exist (e.g., the crystal oscillator-based clocks in every personal computer, GPS signals, etc.), they either lack (usable) traceable calibration, require additional hardware, or both. A calibrated manually operated stopwatch / chronometer can be used as a reference. While this meets the requirement for traceable calibration, the manual process of starting and stopping the timepiece adds considerable inaccuracy and is dependent on the operator performing the calibration. Summary of the Invention

[0008] Based on the above, the problem to be solved by the present invention is to provide a system and method for achieving traceable calibration of device timers, especially involving sampling of correct mass or volume, wherein it is desired to accurately determine the time interval for performing analysis (for example, the time interval over which the mass or flow of the fluid needs to be integrated).

[0009] This problem is solved by the system of claim 1 and the method of claim 12 .

[0010] Preferred embodiments of these aspects of the invention are set out in the respective dependent claims and are also described below.

[0011] According to claim 1, a system for calibrating a timer is disclosed, the system comprising:

[0012] - a device comprising a timer, wherein the device is preferably configured to use the timer for analysis (e.g. measuring the duration of an event or activity) and / or to use the timer in a control loop (e.g. controlling the duration of an event or activity),

[0013] in,

[0014] The device is configured to time a reference time interval T based on the expiration of a timer on a reference time server, preferably a Network Time Protocol (NTP) server. R to calibrate the device's timer.

[0015] In the context of the present invention, the timer of the calibration device preferably corresponds to the time interval T that will have expired on the timer of the device. E The reference time interval T that expires on the timer of the reference time server R Make a comparison.

[0016] According to a preferred embodiment, the device is configured to generate a certificate for recording the calibration result. In particular, as further described below, the calibration result may correspond to or include a time interval T E and reference time interval T R The difference between.

[0017] In a preferred embodiment of the system according to the present invention, the reference time server is an NTP server. While NTP servers are commonly used to adjust the system time (absolute time) of a computer system (e.g., a personal computer or mobile phone), the present invention is not concerned with absolute time. Instead, the present invention relies on a reference time server / NTP server to obtain accurate information about durations in order to calibrate timers or clocks that are only concerned with durations (and may not even know absolute time).

[0018] Therefore, the present invention relies on a reference time server (preferably an NTP server) to provide a calibration reference, wherein preferably a time reference server (especially an NTP server) operated by a (national) metrology institute is selected so as to enable calibration traceable to a (national) calibration standard. Examples of such metrology institutes responsible for national reference time (provided by NTP servers) are: the Swiss Federal Institute of Metrology (METAS), the French National Laboratory for Metrology and Testing - Space and Time Reference System (LNE-SYRTE), and the US National Institute of Standards and Technology (NIST).

[0019] Using such a reference time server / NTP server as a reference timer makes timer calibration results particularly traceable, without having to rely on a calibrated manual stopwatch. Advantageously, the calibration process can, in principle, be fully automated. Furthermore, communication delays with the reference time server (and, if applicable, the timer being calibrated) can be taken into account, further improving accuracy.

[0020] In a preferred embodiment, the present invention is applied to a microbial air sampler. However, the present invention can be used with any device that requires a calibrated timer (e.g., air samplers, particle counters, biological analysis equipment, etc.).

[0021] Specifically, the Network Time Protocol (NTP) is a network protocol for synchronizing clocks between computer systems on packet-switched, variable-latency data networks. NTP allows computers to be synchronized to within a tolerance of a few milliseconds. NTP can typically maintain time accuracy up to tens of milliseconds over the public internet, while higher accuracy can be achieved within local area networks. NTP can be used as a client-server model or for peer-to-peer communication, where, for example, two peers consider each other as a potential time source.

[0022] According to a preferred embodiment of the system, the analysis comprises using a timer of the device to calculate the mass or volume of the fluid, in particular if the timer has been verified to be accurate within a desired tolerance range by calibration or has been adjusted. According to a further preferred embodiment, using the timer in the control loop corresponds to using the timer of the device to control the time period during which a specific mass or volume of fluid passes through the device, in particular if the timer has been verified to be accurate within a desired tolerance range by calibration or has been adjusted.

[0023] Furthermore, according to a preferred embodiment of the system, the device is a microbial air sampler. In particular, the device is configured to extract target particles from the air onto or in a suitable growth medium. In particular, the device is configured to direct a gas / air flow containing particles (e.g., microorganisms or other target particles / substances) to the growth medium so that the particles impinge on the growth medium (which may be provided in the form of a nutrient plate) for subsequent analysis. However, in other preferred embodiments, the device may be any device, in particular a bioanalytical device, which analyzes substances, such as fluids, gases, liquids, in particular with respect to components therein, in particular, for example, particles and / or microorganisms.

[0024] Furthermore, according to a preferred embodiment of the system, the reference time interval T R On the time reference server, timestamp T from the first time reference server NTP,1 Initially, the timestamp is derived from the time of the first request packet received by the time reference server and / or the time of the first response packet sent by the time reference server, and is added to the second time reference server timestamp T NTP,2 End, the timestamp is derived from the time of the second request packet received by the time reference server and / or the time of the second response packet sent by the time reference server.

[0025] In particular, the first time reference server timestamp may correspond to one of: the time at which the time reference server receives the first request packet, the time at which the time reference server sends the first response packet, a time determined based on the time at which the first request packet is received and the time at which the first response packet is sent, and in particular an average value formed by the time at which the first request packet is received and the time at which the first response packet is sent.

[0026] In particular, the second time reference server timestamp may correspond to one of: the time at which the time reference server receives the first request packet, the time at which the time reference server sends the first response packet, a time determined based on the time at which the first request packet is received and the time at which the first response packet is sent, and in particular an average value formed by the time at which the first request packet is received and the time at which the first response packet is sent.

[0027] Furthermore, according to a preferred embodiment of the system, the device is configured to send the first request packet P1 to the time reference server, and create a first client timestamp T when sending the first request packet P1. C,1 , and upon receiving the first response packet R1 (including the timestamp of the time reference server) from the time reference server, create a second client timestamp T C,2 , to indicate that the first request packet P1 is received at the time reference server, and wherein the device is configured to send the second request packet P2 to the time reference server and create a third client timestamp T when sending the second request packet P2 C,3 , and creates a fourth client timestamp T when receiving the second response packet R2 (including the timestamp of the time reference server) from the time reference server C,4 , to indicate that the second request packet P2 is received at the time reference server.

[0028] However, alternatively, only two consecutive client timestamps (e.g., T C,1 and T C,3 , or T C,2 and T C,4 ), and the delay of the time reference (e.g., NTP) signal can be taken into account (i.e., added or subtracted, respectively) to the corresponding client timestamp.

[0029] According to another alternative preferred embodiment of the system according to the present invention, the system comprises a master clock (in the above embodiment, in particular the device itself is the master clock), wherein the master clock is configured to send a first signal to the device at the start of calibration, wherein the device is configured to create a first client timestamp T upon receipt of the first signal C,1 , and the timestamp T C,1 The first signal is sent to the master clock as a first response signal to indicate that the device has received the first signal, wherein when the master clock receives the first response signal, the master clock is configured to send a first request packet to the time reference server, and wherein the master clock is configured to receive a first response packet from the time reference server to indicate that the time reference server has received the first request packet, and wherein, upon receiving the first response packet, the master clock is configured to send a second signal to the device, wherein the device is configured to create a second client timestamp T when receiving the second signal. C,2 and by taking the second timestamp T C,2 The first response packet from the time reference server includes a first time reference server timestamp and a second response signal sent to the master clock to confirm receipt of the second signal.

[0030] Furthermore, the master clock is configured to send a third signal to the device after expiry of a predetermined time span (the time span notably corresponding to a nominal time period to be used for calibration, ie T E and T R ), wherein the device is configured to create a third client timestamp T when receiving the third signal C,3 , and the third timestamp T C,3 The device sends a third signal as a third response signal to the master clock to indicate that the device has received the third signal, wherein when the master clock receives the third response signal, the master clock is configured to send a second request packet to the time reference server, and wherein the master clock is configured to receive a second response packet from the time reference server to indicate that the time reference server has received the second request packet, and wherein, upon receiving the second response packet, the master clock is configured to send a fourth signal to the device, wherein the device is configured to create a fourth client timestamp T when receiving the fourth signal. C,4 and by adding the fourth timestamp T C,4 The fourth response signal is sent to the master clock to confirm receipt of the fourth signal. In particular, the second response packet from the time reference server includes a second time reference server timestamp.

[0031] According to an alternative embodiment, the first, second, third and fourth response signals do not need to include the client timestamp T C,1 ,…,T C,4 The latter can process client timestamps on the master clock (e.g., T E any time before that sent by the device to the master clock.

[0032] In particular, note that the client timestamp T C,1 ,…,T C,4 It does not need to be relative to absolute time or system time.

[0033] Furthermore, according to a preferred embodiment of the system of the present invention, the device or system is configured to use at least the client timestamp T C,1 ,…,T C,4 To calculate the time interval T that has expired on the timer of the device E , wherein in particular, the device is configured to set the time interval T E Calculated as T E =[(T C,3 -T C,1 )+(T C,4 -T C,2 )] / 2, and the time interval T E With reference time interval T R For comparison, especially according to T R =TNTP,2 -T NTP,1 Calculation is performed, wherein the system is configured to perform one of the following operations: using the time interval T E and reference time interval T R The timer is adjusted by the difference between the two; the time interval T is used in subsequent calculations / analysis E and reference time interval T R The difference between the two; in the time interval T E and reference time interval T R The timer is not used if the absolute difference between the two exceeds a predetermined threshold.

[0034] As mentioned before, according to a preferred embodiment of the system, the time reference server is a remote time reference server of a national metrology institute (see also above), in particular a remote NTP server of a national metrology institute.

[0035] Preferably, in a preferred embodiment of the system, the device is configurable by a user to allow the user to select a time reference server from a plurality of available time reference servers.

[0036] According to another aspect of the present invention, a method for calibrating a timer of a device is disclosed, in particular using a system according to the present invention, wherein the method comprises the following steps:

[0037] a) Based on a reference time interval T expiring on a timer of a time reference server R to calibrate the device's timer, and

[0038] b) If the timer is deemed to be inaccurate within a desired tolerance range based on the calibration, not using the timer or adjusting the timer.

[0039] In particular, discarding the timer may also include replacing the timer with a calibrated / accurate timer.

[0040] According to another embodiment of the method, the method further comprises the step of performing an analysis using the timer if the timer is accurate within a desired tolerance range or has been adjusted, wherein in particular the analysis comprises calculating the mass or volume by integrating the mass flow rate or volume flow rate of the fluid using the timer.

[0041] According to an embodiment, the analysis comprises using the time interval T E (See also above) to calculate the flow rate of a fluid, in particular the mass flow rate or volume flow rate of a fluid.

[0042] According to a preferred embodiment of the method, the reference time interval T on the time reference server in step a) R From the first time reference server timestamp TNTP,1 Initially, the timestamp is derived from the time when the time reference server receives the first request packet and / or the time when the time reference server sends the first response packet, and is generated at the second time reference server timestamp T NTP,2 End, the timestamp is derived from the time when the time reference server receives the second request packet and / or the time when the time reference server sends the second response packet.

[0043] In particular, as described above, the first time reference server timestamp may correspond to one of: the time when the time reference server receives the first request packet, the time when the time reference server sends the first response packet, a time determined based on the time of receiving the first request packet and the time of sending the first response packet, in particular an average value formed by the time of receiving the first request packet and the time of sending the first response packet.

[0044] In addition, in particular, the second time reference server timestamp can correspond to one of the following: the time when the time reference server receives the first request packet, the time when the time reference server sends the first response packet, a time determined based on the time of receiving the first request packet and the time of sending the first response packet, in particular an average value formed by the time of receiving the first request packet and the time of sending the first response packet.

[0045] According to a preferred embodiment of the method, step a) further comprises the device sending the first request packet P1 to the time reference server, and the device creating a first client timestamp T when sending the first request packet P1. C,1 , and when the device receives the first response packet R1 of the time reference server (used to indicate that the first request packet P1 is received at the time reference server), it creates a second client timestamp T C,2 , and wherein step a) further comprises the device sending the second request packet P2 to the time reference server, and the device creating a third client timestamp T when sending the second request packet P2. C,3 , and when the device receives the second response packet R2 of the time reference server (used to indicate that the second request packet P2 is received at the time reference server), a fourth client timestamp T is created. C,4 .

[0046] Alternatively, according to another preferred embodiment of the present invention, using a master clock in communication with a time reference server, step a) further comprises:

[0047] The master clock sends a first signal indicating the start of calibration to the device, and the device creates a first client timestamp T when receiving the first signal. C,1, and the device sends a first response signal to the master clock to indicate that the device has received the first signal, wherein the first response signal includes the first client timestamp T C,1 , and when the master clock receives the first response signal, the master clock sends a first request packet P1 to the time reference server, and when the master clock receives a first response packet R1 from the time reference server indicating that the time reference server has received the first request packet P1, the master clock sends a second signal to the device, and the device creates a second client timestamp T when receiving the second signal. C,2 , and the device confirms receipt of the second signal by sending a second response signal to the master clock, wherein the second response signal includes a second client timestamp T C,2 ,as well as

[0048] The master clock sends a third signal to the device after the predetermined time span expires, and the device creates a third client timestamp T when receiving the third signal. C,3 , and the device sends a third response signal to the master clock to indicate that the device has received the third signal, wherein the third response signal includes a third client timestamp T C,3 , and when the master clock receives the third response signal, the master clock sends a second request packet P2 to the time reference server, and when the master clock receives a second response packet R2 from the time reference server indicating that the time reference server has received the second request packet P2, the master clock sends a fourth signal to the device, and the device creates a fourth client timestamp T when receiving the fourth signal. C,4 , and the device confirms receipt of the fourth signal by sending a fourth response signal to the master clock, wherein the fourth response signal includes a fourth client timestamp T C,4 .

[0049] In particular, the first response packet from the time reference server includes the first time reference server timestamp. In addition, in particular, the second response packet from the time reference server includes the second time reference server timestamp.

[0050] As mentioned above, in a preferred embodiment of the method according to the invention, the time interval T which has expired on the timer of the device E The device uses at least the client timestamp (T C,1 ,…,T C,4 ) is automatically calculated, where in particular the time interval T E Automatically calculated by the device as T E =[(T C,3 -T C,1 )+(T C,4 -T C,2)] / 2, and the time interval T E Automatic and reference time interval T R For comparison, the reference time interval T R Specifically, it is automatically calculated as T R =T NTP,2 -T NTP,1 , where, in the time interval T E With reference time interval T R If the difference exceeds a predetermined amount, the timer is considered to be inaccurate within the desired tolerance range, and the timer of the device will be discarded (e.g., taken out of use or removed) or adjusted and calibrated.

[0051] According to a preferred embodiment of the method according to the invention, the time reference server is an NTP server (see also above).Furthermore, according to a preferred embodiment of the method according to the invention, the time reference server is a remote time reference server of a national metrology institute, in particular a remote NTP server of a national metrology institute.

[0052] Furthermore, according to a preferred embodiment of the method, the time reference server is selected by a user from a plurality of available time reference servers. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In the following, embodiments of the invention as well as further features, advantages and other aspects of the invention will be described with reference to the accompanying drawings, in which:

[0054] Figure 1 An embodiment of the system and method according to the invention is shown, wherein here a device comprising a timer to be calibrated communicates with a time reference server, preferably an NTP server, and,

[0055] Figure 2 An alternative embodiment is shown, wherein here the device is calibrated by a master clock communicating with a time reference server, preferably an NTP server. DETAILED DESCRIPTION

[0056] Figure 1 and Figure 2 Two embodiments of the system and method according to the invention are shown, wherein the device 1 comprises a timepiece 10 to be calibrated.

[0057] Preferably, a calibration of the timer 10 to an NTP (Network Time Protocol) server is performed, which is preferably operated by a (national) metrology institute, thereby providing traceability. Although NTP is traditionally intended and used to synchronize the absolute time (RTC - Real Time Clock) of a local computer or instrument, the present invention proposes to use NTP here to calibrate the timer 10 of the local device 1 to the reference time interval T of the NTP server 2. RThe difference / expiration time is not relevant (i.e., the absolute current time is irrelevant). Other time reference servers besides NTP servers can also be used.

[0058] Advantageously, such a calibration process can be automated, wherein the NTP server 2 used is preferably configurable by the user, thereby selecting the reference used, such as a (national) metrology institute (to obtain traceability) or even an NTP server within the company network (if traceability is not important or there is no internet access).

[0059] In each of the illustrated embodiments, there is a timer 10 of a device 1 that needs calibration and an NTP server 2 that serves as a reference.

[0060] In a preferred embodiment, the master device controlling the process corresponds to device 1 itself. Figure 1 A preferred calibration sequence is shown. Figure 1 A preferred calibration sequence is shown.

[0061] In particular, from Figure 1 It can be seen that the following relationship is used:

[0062] Reference time interval T R T R =T NTP,2 -T NTP,1 .

[0063] The time interval T that elapses on device 1 E Obtained according to the following formula:

[0064] T E =[(T C,3 -T C,1 )+(T C,4 -T C,2 )] / 2;

[0065] Where T C,1 To T C,4 Indicates the first to fourth client timestamps.

[0066] The time deviation between two intervals corresponds to the difference: T E -T R , which can be used to calibrate the device. In addition, the difference can be used to adjust the timer and / or adjust subsequent calculations performed by the system / device 1.

[0067] The basic implementation above makes some assumptions that contribute to the uncertainty of the method, namely ignoring the delay differences with the NTP server and internal NTP delays.

[0068] Specifically, the calibration is performed as follows. Figure 1As shown, the reference time interval TR on the NTP server 2 is from the first NTP server timestamp T NTP,1 Initially, the timestamp is derived from the time of the first request packet P1 received by the NTP server 2 and / or the time of the first response packet R1 sent by the NTP server 2, and is added to the second NTP server timestamp T NTP,2 End, the timestamp is derived from the time when the second request packet P2 is received by the NTP server 2 and / or the time when the second response packet R2 is sent by the NTP server 2.

[0069] In addition, the device 1 is configured to send the first request packet P1 to the NTP server 2, and create a first client timestamp T when sending the first request packet P1. C,1 , and creates a second client timestamp T when receiving the first response packet R1 from NTP server 2 C,2 In addition, the device 1 is configured to send the second request packet P2 to the NTP server 2 after the predefined time span expires, and to create a third client timestamp T when sending the second request packet P2. C,3 , and creates a fourth client timestamp T when receiving the second response packet R2 from NTP server 2 C,4 In particular, the corresponding response packet from the NTP server contains the corresponding (first or second) NTP server timestamp.

[0070] In another preferred implementation, the timer 10 that requires calibration is separate from the master clock that controls the process. Figure 2 A preferred calibration sequence for this setup is shown.

[0071] Again, some assumptions are made that lead to uncertainty in this method. In particular, the delay difference with NTP, the delay within NTP, and the delay difference with the device under test are ignored.

[0072] However, note that in Figure 2 In the example of FIG. 3 , the timer of the master clock 3 may result in a target duration (time interval T E ) is inaccurate, but this does not lead to inaccurate calibration results.

[0073] In particular, in the case of using the master clock 3, the calibration is carried out as follows (see Figure 2 The master clock 3 is configured to send a first signal 31 to the device 1, wherein the device 1 is configured to create a first client timestamp T upon receiving the first signal 31. C,1 , and sends the first client timestamp T to the master clock 3 C,1The master clock 3 receives a first response signal 41 to indicate that the device 1 has received the first signal 31, wherein when the master clock 3 receives the first response signal 41, the master clock 3 is configured to send a first request packet P1 to the NTP server 2. In addition, the master clock 3 is configured to receive a first response packet R1 from the NTP server 2 indicating that the NTP server 2 has received the first request packet P1, and when receiving the first response packet R1, the master clock 3 is configured to send a second signal 32 to the device 1, wherein the device 1 is configured to create a second client timestamp T when receiving the second signal 32. C,2 , and sends the second client timestamp T to the master clock 3 C,2 The second response signal 42 is received to confirm the receipt of the second signal 32.

[0074] Furthermore, the master clock 3 is configured to send a third signal 33 to the device 1 after expiration of the predefined time span, wherein the device 1 is configured to create a third client timestamp T upon receipt of the third signal 33. C,3 , and sends the third client timestamp T to the master clock 3 C,3 The master clock 3 receives a third response signal 43 to indicate that the device 1 has received the third signal 33, wherein when the master clock receives the third response signal 43, the master clock 3 is configured to send a second request packet P2 to the NTP server 2. In addition, the master clock 3 is configured to receive a second response packet R2 from the NTP server 2 indicating that the NTP server 2 has received the second request packet P2, and, upon receiving the second response packet R2, the master clock 3 is configured to send a fourth signal 34 to the device 1, wherein the device 1 is configured to create a fourth client timestamp T when receiving the fourth signal 34. C,4 and sends a fourth client timestamp T to the master clock 3 C,4 The fourth response signal 44 is used to confirm the receipt of the fourth signal 34.

[0075] Here also, as described above, the device 1 is configured to use at least the client timestamp T C,1 ,…,T C,4 To calculate the time interval T that has expired on the timer 10 of the device E , wherein, in particular, the device is configured to set the time interval T E Calculated as T E =[(T C,3 -T C,1 )+(T C,4 -T C,2 )] / 2, and the time interval T E With reference time interval T R For comparison, the reference time interval T R Especially according to T R =TNTP,2 -T NTP,1 In the above two embodiments, the system or device is specifically configured to perform one of the following operations: using the time interval T E and reference time interval T R The timer 10 is adjusted by the difference between the two; the time interval T is used in subsequent calculations / analysis E and reference time interval T R The difference between the two; in the time interval T E and reference time interval T R If the absolute difference between φ and φ exceeds a predefined threshold, the timer 10 is not used.

[0076] The implementation described above uses a simple but efficient algorithm and accepts the corresponding uncertainty. Calibration accuracy can be improved by incorporating methods commonly recommended and applied for adjusting / calibrating, for example, a personal computer's real-time clock to an NTP server. For example, instead of making a single call to NTP and the device, repeated calls can be made, and the calibration can be performed using the one or pair with the shortest delay. This results in higher accuracy, based on the assumption that shorter delays are associated with smaller differences between send and receive delays.

Claims

1. A system for calibrating a timer, comprising: Device (1) comprising a timer (10), wherein the device (1) is configured to use the timer (10) for analysis and / or to use the timer (10) in a control loop, wherein, The system is configured to be based on a reference time interval T expiring on a timer (20) of a time reference server (2) R To calibrate the timer (10) of the device (1).

2. The system according to claim 1, wherein: The time reference server (2) is an NTP server (2).

3. The system according to claim 1 or 2, wherein: The device (1) is configured to generate a certificate for recording a calibration result.

4. A system according to any one of the preceding claims, wherein: The analysis comprises calculating the mass or volume by integrating the mass flow rate or volume flow rate of the fluid using the timer (10) of the device (1), and / or, wherein using the timer (10) in a control loop corresponds to using the timer (10) of the device (1) to control the time period during which a specific mass or volume of fluid passes through the device (1).

5. A system according to any one of the preceding claims, wherein: The device (1) is one of the following: a biological analysis device, a particle collection device, a microbial air sampler.

6. A system according to any one of the preceding claims, wherein: The reference time interval T on the time reference server (2) R From the first time reference server timestamp (T NTP,1 ), the first time reference server timestamp is derived from the time of the first request packet (P1) received by the time reference server (2) and / or the time of the first response packet (R1) sent by the time reference server (2), and is generated at the second time reference server timestamp (T NTP,2 ) ends, the second time reference server timestamp originating from the time of the second request packet (P2) received by the time reference server (2) and / or the time of the second response packet (R2) sent by the time reference server (2).

7. The system according to claim 6, wherein: The device (1) is configured to send the first request packet (P1) to the time reference server (2) and to create a first client timestamp (T C,1 ), and creates a second client timestamp (T C,2 ), and wherein the device (1) is configured to send the second request packet (P2) to the time reference server (2) after a predefined time span expires, and to create a third client timestamp (T C,3 ), and creates a fourth client timestamp (T C,4 ).

8. The system according to claim 6, wherein: The system comprises a master clock (3), wherein The master clock (3) is configured to send a first signal (31) to the device (1), wherein the device (1) is configured to create a first client timestamp (T C,1 ), and sends a message including the first client timestamp (T C,1 ) to indicate that the device (1) has received the first signal (31), wherein, when the master clock (3) receives the first response signal (41), the master clock (3) is configured to send the first request packet (P1) to the time reference server (2), and wherein, the master clock (3) is configured to receive a first response packet (R1) from the time reference server (2) indicating that the time reference server (2) has received the first request packet (P1), and wherein, upon receiving the first response packet (R1), the master clock (3) is configured to send a second signal (32) to the device (1), wherein the device (1) is configured to create a second client timestamp (T) upon receiving the second signal (32). C,2 ), and sends a second client timestamp (T C,2 ) to confirm receipt of the second signal (32), and wherein The master clock (3) is configured to send a third signal (33) to the device (1) after a predefined time span has expired, wherein the device (1) is configured to create a third client timestamp (T C,3 ), and sends a message including the third client timestamp (T C,3 ), to indicate that the device (1) has received the third signal (33), wherein, when the master clock receives the third response signal (43), the master clock (3) is configured to send the second request packet (P2) to the time reference server (2), and wherein, the master clock (3) is configured to receive a second response packet (R2) from the time reference server (2) indicating that the time reference server (2) has received the second request packet (P2), and wherein, upon receiving the second response packet (R2), the master clock (3) is configured to send a fourth signal (34) to the device (1), wherein the device (1) is configured to create a fourth client timestamp (T C,4 ), and sends a message including the fourth client timestamp (T C,4 ) to confirm receipt of the fourth signal (34).

9. The system according to claim 7 or 8, wherein: The device (1) is configured to use at least the client timestamp (T C,1 ,…,T C,4 ) to calculate the time interval T that has expired on the timer (10) of the device E , wherein in particular, the device is configured to set the time interval T E Calculated as T E =[(T C,3 -T C,1 )+(T C,4 -T C,2 )] / 2, and the time interval T E and the reference time interval T R For comparison, the reference time interval T R Especially according to T R =T NTP,2 -T NTP,1 Calculation, wherein the system is configured to perform one of the following operations: using the time interval T E and the reference time interval T R The timer (10) is adjusted by the difference between the two; the time interval T is used in subsequent calculations E and the reference time interval T R The difference between the two; in the time interval T E and the reference time interval T R The timer (10) is not used if the absolute difference between exceeds a predefined threshold.

10. A system according to any one of the preceding claims, wherein The time reference server (2) is a time reference server of a national metrology institute.

11. A system according to any one of the preceding claims, wherein: The device (1) is configurable by a user to allow the user to select the time reference server (2) from a plurality of available time reference servers.

12. A method for calibrating a timer (10) of a device (1), in particular using a device (1) according to any one of the preceding claims, comprising the following steps: a) based on a reference time interval (T R ) to calibrate the timer (10) of the device (1), and b) not using the timer (10) or adjusting the timer (10) if the timer is not accurate within a desired tolerance.

13. The method according to claim 12, wherein: The method further comprises the step of performing an analysis using the timer (10) if the timer (10) is accurate within a desired tolerance, wherein in particular the analysis comprises calculating the mass or volume by integrating the mass flow rate or volume flow rate of the fluid using the timer (10).

14. The method according to any one of claims 12 to 13, wherein The reference time interval (T R ) from the first time reference server timestamp (T NTP,1 ), the first time reference server timestamp is derived from the time of the first request packet (P1) received by the time reference server (2) and / or the time of the first response packet (R1) sent by the time reference server (2), and is generated at the second time reference server timestamp (T NTP,2 ) ends, the second time reference server timestamp originating from the time of the second request packet (P2) received by the time reference server (2) and / or the time of the second response packet (R2) sent by the time reference server (2).

15. The method according to claim 14, wherein Step a) further comprises: the device (1) sending the first request packet (P1) to the time reference server (2), and the device (1) creating a first client timestamp (T C,1 ), and the device (1) creates a second client timestamp (T) when receiving a first response packet (R1) from the time reference server (2) indicating that the time reference server (2) has received the first request packet (P1). C,2 ), and wherein step a) further comprises the device (1) sending the second request packet (P2) to the time reference server (2), and the device (1) creating a third client timestamp (T C,3 ), and creating a fourth client timestamp (T ) by the device (1) when receiving a second response packet (R2) from the time reference server (2) indicating that the time reference server (2) has received the second request packet (R2). C,4 ).

16. The method according to claim 14, wherein Step a) further comprises: The master clock (3) sends a first signal (31) to the device (1), and the device (1) creates a first client timestamp (T C,1 ), and the device (1) sends a first response signal (41) to the master clock (3) to indicate that the device (1) has received the first signal (31), wherein the first response signal (41) includes the first client timestamp (T C,1 ), and when the master clock (3) receives the first response signal (41), the master clock (3) sends the first request packet (P1) to the time reference server (2), and when the master clock (3) receives the first response packet (R1) from the time reference server (2) indicating that the time reference server (2) has received the first request packet (P1), the master clock (3) sends a second signal (32) to the device (1), and when the device (1) receives the second signal (32), creates a second client timestamp (T C,2 ), and the device (1) confirms receipt of the second signal (32) by sending a second response signal (42) to the master clock (3), wherein the second response signal (42) includes the second client timestamp (T C,2 ),as well as The master clock (3) sends a third signal (33) to the device (1) after a predefined time span expires, and the device (1) creates a third client timestamp (T C,3 ), and the device (1) sends a third response signal (43) to the master clock (3) to indicate that the device (1) has received the third signal (33), wherein the third response signal (43) includes the third client timestamp (T C,3 ), and when the master clock (3) receives the third response signal (43), the master clock (3) sends the second request packet (P2) to the time reference server (2), and when the master clock (3) receives the second response packet (R2) from the time reference server (2) indicating that the time reference server (2) has received the second request packet (P2), the master clock (3) sends a fourth signal (34) to the device (1), and when the device (1) receives the fourth signal (34), creates a fourth client timestamp (T C,4 ), and the device (1) confirms receipt of the fourth signal (34) by sending a fourth response signal (44) to the master clock (3), wherein the fourth response signal (44) includes the fourth client timestamp (T C,4 ).

17. The method according to claim 13 or 14, wherein: The time interval T that has expired on the timer (10) of the device (1) E The device uses at least the client timestamp (T C,1 ,…,T C,4 ) is automatically calculated, wherein in particular, the time interval T E Calculated by the device (1) as T E =[(T C,3 -T C,1 )+(T C,4 -T C,2 )] / 2, and wherein the time interval T E Automatically with the reference time interval T R Compared with the reference time interval T R Especially according to T R =T NTP,2 -T NTP,1 Automatic calculation, where, in the time interval T E and the reference time interval T R If the difference exceeds a predetermined amount, the timer (10) is deemed to have failed to meet the accuracy requirement within the desired tolerance range.

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