JPH02503036A - How to calibrate and operate scales and scales - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] How to calibrate and operate scales and scales This invention allows the weight of the object to be weighed to be compared to the weight of a reference mass and the scale to be A positive value is required, and even in the case of an oblique arrangement, if the gravitational acceleration g is deviated from the normal value. In this case, the mass of the weighed object can be determined properly without post-calibration, and the diagonal arrangement This can be compared to a considerable reduction in force acceleration.

Concerning a scale as a true mass measuring instrument.

Such scales are described, for example, in Swiss patent no. 492.961 and in Swiss patent no. It is well known from document No. B 03.791787-5. This is an old Purely mechanical.

A constant ratio of the mass of the weighed object to the reference mass, such as a retail scale with a weight or a tilting frame. It operates according to the principle of comparison. Unlike mechanical balances that balance and self-balance , what is disclosed in the two above-mentioned specifications each uses one sensor. It consists of two force measuring instruments that are tightly constrained.

Furthermore, simple force measuring devices that are used as scales are also known. However, this The so-called scales work accurately only under the following conditions:

- Accurate leveling.

- In-situ calibration with a calibration load of known mass.

- Vibration-free operation of the scale.

The problem solved by this invention is that the weight of the weighed object is compared with the weight of the reference mass and Its independence from the configuration and its local deviation from the normal value of the gravitational acceleration Independence lies in providing a scale that can be achieved with little consumption.

The solution to the above-mentioned problem H is achieved by the features of claim IK leading to the device and the method claims. This is achieved by the requirement 12.

Embodiments of the inventive concept will be described in detail with reference to the accompanying drawings.

FIG. 1 is a diagrammatic illustration of a first embodiment with a directly acting reference mass;

FIG. 2 is a diagrammatic illustration of a second embodiment with a reference mass being transformed.

FIG. 3 shows an arrangement with an elastically reducing parallel guide 8 and a directly acting reference mass. The third example is shown below.

FIG. 4 shows a fourth embodiment with a transformed and operative reference mass.

FIG. 5 shows a fifth embodiment with a removable weighing pan.

The first embodiment according to FIG. 1 consists of a pedestal l and a load support 2. The body is guided in parallel by two plates 4.5 arranged in the joint 3. scale The weight of the weighing object - represented by weight 8 in FIG. be reached. According to this, the load support body 2 is rigidly restrained.

A mass 9 is further fixed to the load support 2 . Effective weight and load support of plate 4゜5 The weight of body 2 and the weight of mass 9 are - together, the force when the load support is . A reference force that acts on a total of 7 is formed. Electrical signal sent from force meter – analog or is supplied to the computer 10 via a cable 11. In Figure 1 The computer 10 is connected to a pedestal. Lengthen cable 11.

It is natural within the meaning of this invention that the calculator 11 can be made to stand on its own. . The embodiment according to FIG. 2 is constructed essentially the same as that of FIG. The difference is The method of fixing the mass 9 and the method of action. A support 13 is firmly connected to the frame l. , which supports the lever 15 at the joint 14 . At the end of lever 15, Mass 9 is fixed. Its weight is flexibly attached to the load support 2 and to the lever 15. It acts on the load support 2 via the tension band 16 . Compared to the first embodiment , in this embodiment, the mass 9 can be made smaller, which reduces the weight of the scale. has advantages.

Another embodiment is shown in FIG. The lower part of the force measuring device has been applied for a Swiss patent. It is known from specification no. 03040787-A. This is from board 32 A pedestal 21 is fixed on top of this. /gundo joint 2 in this frame 21 Two plates 25, 28 with 6.27 are articulated to the load support 22. negative Between the upper part of the load support 22 and the lower part of the frame 21, the above-mentioned elements A foot 27 extends diagonally through the parallel guide formed, which is responsible for the force to be measured. is transmitted to force meter 7. A frame plate 36 is fixed on top of the load support 22, which has a mass I support 9. The object to be weighed is again symbolized by a weight 8. hard restraint is achieved here also by the foot 17 and the force meter 7. 1 elastic flat attached A stop 35 is provided to protect the row guide from passing loads. Calculator from force meter 7 The connection to 10 is again made via a cable 11.

In FIG. 4, the weight of mass 9 is again supplied converted. upper board One end of a lever 18 is fixed to 23, which supports a mass of 9 tons at the other end. scale The other parts are the same as the embodiment according to FIG.

The embodiment according to FIG. 5 is based - for example - on that according to FIG. The embodiment according to FIG. 4 is also included in the concept of the invention. In this case, a support, for example a plate 29, is fixed on the load support 22. Board 2 9 is four rods 30 (only two of them are shown in FIG. 5 because it is a side view). support. These rods 30 are attached to the underside of a removable weighing pan 37 here and here. It is introduced into a suitable fitting part 31 which has been provided. The four tributes 30 are closed planks 38 a single mechanical part led out through an opening 39 from the opening 39. From Figure 1 to Figure 4 In contrast to the embodiment according to the invention, here the weighing pan 37 is not part of the reference mass.

Furthermore, it is also within the concept of this invention that the board 29 is provided with a number of rods 30 other than four. include. In the case of a rounded weighing pan 37, three rods 30 should be suitable for the purpose. - When using a partial weighing pan, such as an ordinary analytical balance, a single rod 30 is shown. In the last case, the plate 29 can be omitted and the shaft 30 directly carries the load. It is attached to the holder 22 and swings. At that time, the number of fitting parts 31 and, depending on the case, The structure also changes correspondingly.

It's obvious.

In another embodiment (not shown) (numbers refer to elements in FIG. 5), many forces A total of seven, for example three, are fixed on the substrate 32. Each force meter 7 is equal to i Each force bearing one mass 9 and having an umbilical mass 9 on which a rod 30 is fixed A total of 7 is enclosed within a paneling 38 having an opening 39 through which a rod 30 is inserted. stands out. The number and arrangement of Zen 30 are as follows: , and this balance bridge therefore has the rods 30 from the force meter 7 described above. Supported by Each force meter 7 has 1. calibrated.

The weight of the object to be weighed is determined by accumulating the weight results of the individual dynamometers in the calculator 10. This is achieved by K. If the balance bridge is heavy, the mass 9 can be omitted. Sara Calibration and determination of the reference force of one force meter is based on the mass of the balance bridge only (.

The common assumption for all the above-mentioned embodiments is that the force meter 7 corresponding to the prior art In this case, the introduced force is uniquely converted into an electrical signal. It will be done.

This is the case with digital crystal transducers or vibrating string transducers, for example. If it is an electrical signal, if it is an analog electrical signal, the force meter 7 and the An AD converter is interposed between the computers 10. Still need 7 force meters or Linearization of the degree course and computer compensation of the entire force-measuring device are not available in the prior art. be. Balances so linearized and temperature compensated are calibrated by the manufacturer. .

The calibration method consists of the following steps. The first calibration is when the scale is horizontal K (tilt angle α1 ), and a second calibration is performed when the scale is in an oblique position (α2). principle On the other hand, this will never mean that α1=0. On the other hand, as has been shown, it is not necessary. . The concept ``kara-no-kei'' used repeatedly below refers to ``the scale in the standard state'', which means a ``scale in the standard state''. Taste. For the embodiments according to FIGS. 1 to 4, this means a literal "load-bearing This means that there is nothing on the support 2 or the frame plate 36. In the example shown in FIG. In contrast, this means that "the weighing pan 37 is removed". empty horizontal scales In this case, the calculator IO determines the reference value R1 and the horse, respectively. Then the scale - once again subtract the calibration weight acting under the full load of one mass m each horizontally and diagonally. load Value determined by calculator 10.

are Ml and Ml. Next, these four values are attached to the M-Ki military aircraft lO. Stored in fixed value memory.

Calibration and weighing methods are based on first-order considerations and calculations.

In principle, starting from an elastic preload which itself is not precisely known, The following formula holds true for the reference value.

R1==V+a(go+Δg)mRcowα1R2==V+a(g O+Δg) m Rc o sα2 where V = elastic preload a = proportionality coefficient mp　Effective reference mass α1 = angle of inclination of the scale Δg = deviation of gravitational acceleration from normal value g, in this case Δg base 0゜g = go + Δg For the full load values M and Ml, the following equations further hold true.

Ml==V+a(gO+Δg)(mB”mL) eolIα1M2= = V + a (go + Δg) (mR + mL) eolα2 where, ■ and a , mR, α1. The assumption is that α2 and Δg are not precisely known. . For computer handling, some transformations are performed. Diagonal placement.

Since it acts in the same way as the change in g, a(go+Δg)eoIα,"tkgo,(I"hl)="g, and to =ag(1+e) Then, it becomes the first order.

R1=V + emRfil R2==V+CmFl(1+@) f2+M1=V+ e(mPI+mL) ta+M2=V+c(mR+mL )(1+e) +41The relevant difference between the full load and the reference value is thus: It is expressed as follows.

Ll'::MI R1=emL (5) R2=Ml R2=cm), (1+e) f6! These values and R2 are also stored be done. Next - 1, some processing is performed by the computer as explained next. It will be done.

Weighing an unknown mass m when the weight and slope ratio are unknown. , the following formula holds true for the reference value (for scales from).

R engineering = = V + a (g (1 + Δg) mReos α engineering = V + ig (+ +h,)mR =V + emR(l+x) +71=c(1+x) moreover, From Mx=V+e(1+x)(m,+m-work), it becomes as follows.

L, = e (1”x) mx known from t81 calibration The quantities are R, F　R2, Llt　R2 and mL, and the unknown quantities associated with the device are e, m, e, and V. This becomes clear as follows.

From (5) and (6) e = (R2-Ll) / L, from Cl1l (1), (2) and aa “R” IIDL (R2R1) / (R2Ll) +111 here .

(R2-R1)/(R2-L,)=P 113 then 1 It can be written as follows.

m,: PmL03 Finally from (1) and 0 V　　　　　Rt　-erfiR = R, -PL, 114+. (9), R 3 and aa, the following formula is obtained from [7I.

1+! = (Rx-V)/CmR = (R, -(R, -PL, ))/PL, fil So, from , for the required quantity mK, as follows: L, mLP/(Rx-(R1-PL, )) 71B So, for the determination of an unknown mass, the calibration value R1 and Ll and the mass value mL of the calibration weight should ultimately be stored. Ru. The quantities R2, M, , 8 and L2 are.

From this the quantity P (formula (I3)) can be formed and then deleted.

The first order applies to the reference amount ~ which appears nBK conspicuously. calculator 1 It is prior art to define a zone with a neutralization rate of 0, a so-called zero value zone. scale If the measured value determined from is within this zero value area, the scale The resulting measurement is interpreted as a new zero value. zero The value areas can be symmetrically or asymmetrically, depending on the bias condition and calibration specifications, respectively. can also be configured. Now, the scale according to the present invention is in the standard state (the scale or the scale plate 37). (removal), the required reference quantity R is included in the zero value area.

Then Rx is stored and, if necessary, offset allowed inside the zero value area. is corrected. The stored value R is used for all its functions until the reference condition occurs again. Applies to subsequent weighings.

Determining the reference quantity Rx is necessary for each subsequent weighing during the intervention of Calculation@10. This is the premise. For this purpose, in the embodiment according to FIG. 5, the weighing pan 37 is removed. must be In that case, the weight of the weighing plate 37 is determined after determining the reference amount R. Causes the first weighing and is automatically subtracted as a tare for all subsequent weighing results. It will be done. When another weighing pan 37 is to be loaded, the scale according to the invention returns to its standard state. RX is newly determined, and the weight of the new weighing pan 37 is stored as a new tare. It will be done. Possible subsequent taring operations are: - Corresponding to the prior art, by the user of the weigher; It should be done.

Each weight is therefore, in principle, an instantaneous reference quantity R at that location, which is temporarily stored. Prior to determining x, the weigher supplies the value Lx = M knee and from this - 5 - The mass value m of the weighed object is calculated.

international search report international search report PCT/CH891000 (17 SA　26074

Claims (14)

[Claims] 1. The weight of the weighed object is compared to the weight of the reference mass, and the scale requires calibration only by the manufacturer. Therefore, even in the case of diagonal arrangement and when the gravitational acceleration g deviates from the normal value, the The mass of the weighed object can be determined properly without calibration, and the diagonal arrangement In a scale as a true mass measuring device, the elastic force can be compared to a considerable reduction in the fixed mass (9) of the force transmission chain and another For measuring the effective weight force of a heavy part and in a loaded scale, the reference force The presence of a single force meter (7) for measuring the sum of the weight force and the effective weight force of the weighed object and for storing the quantities determined during the calibration and for recording during the calibration. The quantities R1, R2, which were accepted during the determination of the memorized quantities and reference forces and the subsequent weighing; From L1, L2, Rx, Lx, to determine the appropriate mass value (m) of the weighed object. , there is a calculator (10) equipped with a fixed value memory, and the calculator (10) has a zero value section. A scale characterized in that a range is determined in advance and stored. 2. The scale is mounted on a load support that is guided in parallel by a pedestal (1) and two plates (4, 5). It consists of a holder (2), which controls the weight and mass (9) of the object to be weighed and another movable part of the scale. The effective weight of the sections (2, 4, 5) is transferred via the foot (6) to a single dynamometer (7). The single force meter (7) transmits the mass (9), the load, which together form the reference force. The effective weight of the support (2), plates (4, 5) and feet (6) can be added continuously In addition, when weighing, in addition to the reference force, apply a force from the foot (6) to the weight of the object to be weighed. 2. A scale according to claim 1, further comprising: transmitting a signal to a meter. 3. Claim characterized in that the mass (9) is rigidly connected to the load support (2) The scale described in item 2. 4. Additionally, a lever (15) is present, the mass (9) being one of the levers (15). The other end of the lever (15) is connected to the frame (1) via the joint (14). and that there is a tension band (16) between the ends of the lever (15). , which flexibly connects the lever (15) to the load carrier (2), so that the mass (9) A claim characterized in that an action is performed to transmit the weight force of the force to the dynamometer (7) The scale described in item 2. 5. The scale is guided in parallel by a pedestal (21) and two plates (23, 24). and a load support (22), in which case the plates (23, 24) are connected to the frame (21). and to the load support (22) by means of elastic band joints (25 to 28). being connected, the force meter (7) is connected to the parallelism formed by the elements (21 to 28). The operation of the foot (17), which is integrated obliquely into the guide and is connected to the load support (22) The force transmitted from the foot (17) to the dynamometer (7) is In the reference state, in addition to the elastic preload, the mass (9) and the part (22 to 2 8), and in the loaded state, further from the effective gravity force of the weighed object. The scale according to claim 1, characterized in that: 6. Claim characterized in that the mass (9) is rigidly connected to the load support (22) The scale described in item 5. 7. There is an additional lever (18), one end of which is connected to the plate (23), and the other The end supports the mass (9) so that the weight force of the mass (9) is converted into a load support. 6. A scale according to claim 5, characterized in that it is actuated by. 8. A load support (22) is rigidly connected to this load support for receiving the weighed object. The scale according to claim 6 or 7, characterized in that it supports a replate (36) that has been . 9. A load support (22) supports a plate (29) rigidly connected to it, which , comprising at least one bar (30) and furthermore there is a planking (38), which The scale is provided with a number of apertures (39) corresponding to the number of bars, and surrounds the scale. The rods (30) project through the openings (39), each rod (30) It is characterized by being able to be introduced into the fitting part (31) on the lower side of the weighing plate (37). The scale according to claim 6 or 7. 10. There is a single rod (30) which carries the load when the plate (29) is omitted. Balance according to claim 9, characterized in that it is mounted directly on the support (22). 11. that the dynamometer (7) exists in multiple configurations, that all dynamometers (7) each with a rod (30), by means of which a common weighing bridge is supported; This has a number and arrangement of force meters (7) on its underside that corresponds to the number and arrangement of force meters (7). A fitting part (31), a calculator (10) and its fixed value memory stores the values R1, R2, L1, L2, Rx and Lx of each force meter (7), and , the mass value (mx) is formed based on the sum of the results of the individual force meters. The scale according to claim 1. 12. A method for calibrating and operating a scale according to any one of claims 1 to 11. When calibrating, even in a horizontal position (index 1), if tilted by an angle α2 Also (index 2), the scale measurements from (reference quantities R1, R2) and corresponding to the full load. The measured values (M1, M2) of the sample loaded with the mass (mL) are calculated using the calculator (10). Confirm and memorize it, and calculate the amount using a calculator from now on. L1=M1-R1 L2=M2-R2 and P=(R2-R1)/(L2-L1) , which again eliminates the values M1, R2, M2 and L2 and makes the values R1, L1 Continue to memorize When weighing an unknown mass when the ratio of forces is unknown, first determine the reference quantity (Rx) in the reference state and then the quantity Mx in the loaded state, and forming therefrom a quantity Lx=Mx−Rx and temporarily storing it together with Rx; , the amount existing in fixed memory (R1, L1, P, mL) and the newly received temporarily From the stored values (Rx, Lx), the true amount of mass (mx) to be determined is determined using the formula It is characterized by calculating according to m=Lx・mL・P/Rx−(R1−PL1). how to. 13. Determining the reference quantity (Rx) as soon as the scale is in the zero value area. 13. The method according to claim 12, wherein: 14. The first weight according to the determination of the reference value (Rx) is used as the tare value for each subsequent weight. 14. A method according to claim 13, characterized in that subtracting from the result.