JP2784694B2 - Automatic chemical analyzer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drainage system of a chemical analyzer, and more particularly to a drainage monitoring method for detecting an abnormality at the time of drainage and issuing an alarm.

[0002]

2. Description of the Related Art A reaction vessel used in an automatic chemical analyzer is washed every time an analysis is completed. Usually, in order to perform washing, the reaction solution and washing water contained in the reaction vessel must be drained. FIG. 3 shows an example of an apparatus for this purpose.

In FIG. 3, reference numeral 1 denotes a reaction vessel holding a reaction solution or washing water, 2 denotes a decompression trap, 3 denotes a decompression pump, and 4 has one end inserted into the reaction vessel and the other end inserted into the decompression trap 2. Nozzle. The tip of the nozzle 4 is configured to be insertable into and removable from the reaction vessel 1. 5 is decompression trap 2 at one end
The other end has an exhaust pipe connected to the decompression pump 3, and an opening / closing valve 6 attached to the bottom of the decompression trap 2 for discharging the liquid accumulated in the decompression trap 2.

In such a configuration, the on-off valve 6 is closed,
The nozzle 4 is inserted into the reaction vessel 1 containing the liquid. The depressurizing pump 3 is operated, and the liquid that has entered the reaction vessel 1 is sucked by the depressurizing pump 3 so that the liquid entering the
Is sucked out. Then, the nozzle 4 is inserted into the next reaction vessel 1 containing the liquid, and the liquid is sucked out. The suction of the liquid is repeated several times, and when the trapping limit of the decompression trap 2 is reached, the on-off valve 6 is opened, and the liquid accumulated in the decompression trap 2 is discharged.

[0005] Then, the reaction container 1 from which the liquid has been sucked out contains a liquid for washing or a reagent solution for the next analysis.

[0006]

However, since the nozzles are clogged with precipitates and dirt such as crystals generated in the reaction solution and the washing water, even if the nozzle is sucked and discharged, the reaction solution in the reaction vessel can be removed within a certain period of time. And not all of the washing water is discharged, but a part remains. Then, since a reagent solution or a sample for the next analysis is injected into the reaction vessel in which a part of the reaction solution or the washing solution remains and analyzed, there is a problem that the analysis value varies and the value becomes unreliable. .

An object of the present invention is to provide an apparatus capable of solving such a problem.

[0008]

In order to achieve the above object, an automatic chemical analyzer according to the present invention comprises an automatic chemical analyzer in which a nozzle is inserted into a container, and the liquid in the container is sucked into a decompression trap by a decompression pump and drained. In the chemical analyzer, a pressure gauge for measuring the pressure of the flow path between the nozzle and the decompression trap, a liquid amount in the container and an initial pressure at the time of drainage of the liquid in the container obtained from the pressure gauge A calculating means for obtaining a flow path resistance value of the drainage system from the value and a drainage time obtained from the pressure fluctuation in the drainage; and a comparing means for comparing the result calculated by the calculating means with a predetermined numerical value. It is characterized by having.

[0009]

The initial pressure value at the time of drainage of the liquid in the reaction vessel obtained from the pressure gauge for measuring the amount of liquid in the reaction vessel and the pressure in the flow path between the nozzle and the pressure reducing trap, The drainage time obtained from the pressure fluctuation is calculated from the drainage time and the flow path resistance value of the drainage system at each drainage, and the calculated result is compared with a predetermined value to determine whether the drainage system is clogged. Can be detected.

A method for obtaining the flow path resistance will be described below.

When a nozzle is inserted into the reaction vessel and the liquid in the reaction vessel is sucked into a decompression trap by a decompression pump and drained, the amount of liquid (V) to be drained and the initial pressure (P) before the start of suction are set. ) Is known, the time t required for drainage has the following relationship: t = kVR / P (1) (R: channel resistance, k: constant) Here, the initial pressure P is measurable, and V is the amount of liquid to be drained, which is known on the apparatus. When the drainage time t is measured, R = Pt / kV (2) is obtained from the equation (1), and the flow path resistance R can be known.

Therefore, at the time of drainage during automatic operation of the apparatus, the flow path resistance R at that time is obtained, and the flow path resistance value is compared with the value _R0 obtained at a normal time to determine the presence and degree of clogging of the drainage system. You can know.

[0013]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram showing the operation of the embodiment of the present invention. 1, the same components as those of the conventional example shown in FIG. 3 are denoted by the same reference numerals. In the apparatus of the embodiment shown in FIG. 1, reference numeral 7 denotes a pressure gauge for measuring the pressure during suction of the liquid in the reaction vessel 1 by the nozzle 4. A signal obtained from the pressure gauge is sent to a sampling circuit 8 and a differentiation circuit 9. Reference numeral 10 denotes a time measuring circuit to which an output signal from the differentiating circuit 9 is sent;
Reference numeral 1 denotes a timing circuit for sending operation and measurement timing to the decompression pump 3, the sampling circuit 8 and the time measurement circuit 10,
2 is a storage unit, 13 is a sampling circuit 8, a time measurement circuit 10, and a calculation circuit that calculates based on information sent from the storage unit 12, 14 is a reference signal source, 15 is a result calculated by the calculation circuit and a reference signal. A comparison circuit 16 compares the signal from the source 14, and a control circuit 16 generates an alarm or stops the operation of the cleaning mechanism based on the comparison result of the comparison circuit.

In such a configuration, first, the timing circuit 11 generates a pump drive signal shown in FIG. 2B at time t ₀ so that the pressure reducing pump 3 operates. The pressure reducing pump 3 starts suction based on this signal. Accordingly, the output of the pressure gauge 7 changes as shown in FIG.
After an appropriate time elapses after the decompression pump 3 starts suction, an initial pressure measurement timing signal shown in FIG. 2C is sent from the timing circuit 11 to the sampling circuit 8, and the sampling circuit 8 outputs the output of the pressure gauge 7 at this timing. (Initial pressure P) is sampled. This measured initial pressure P
Is sent from the sampling circuit 8 to the arithmetic circuit 13. Then, at time t ₁ , the tip of the nozzle 4 is inserted into the reaction vessel 1 containing the liquid by a nozzle moving mechanism (not shown), and when the liquid is sucked by the nozzle 4, the pressure is reduced and the output of the pressure gauge 7 is changed as shown in FIG. ) To P '. Thereafter, when the liquid in the reaction vessel 1 runs out, the output of the pressure gauge 7 returns to substantially the same value as the initial pressure. The timing circuit 11 is shown in FIG.
Is generated at time t ₂ to stop the pressure reducing pump, the output of the pressure gauge 7 becomes the atmospheric pressure P ₀ .
Thereafter, the nozzle 4 inserted in the reaction vessel 1 is taken out of the reaction vessel and prepared for a reaction vessel containing the next liquid.

The signal of the pressure change shown in FIG. 2A is sent from the pressure gauge 7 to the differentiating circuit 9, and the differentiated signal shown in FIG. 2D is obtained. The obtained differential signal is sent from the differentiating circuit 9 to the time measuring circuit 10, and at the same time, the timing signal shown in FIG. Time measurement circuit 1
0 measures the time between the second and third derivative peaks,
As a result, the drainage time t shown in FIG. The obtained drain time t is calculated from the time measuring circuit 10 to the arithmetic circuit 1
Sent to 3. Then, the arithmetic circuit 13 sends the liquid volume V and the constant k, which have been input to the storage unit 12 in advance into the reaction vessel 1, the initial pressure P sent from the sampling circuit 8, and the time measurement circuit 10. Drainage time t
, The flow path resistance R is obtained according to the equation (2).
The obtained flow path resistance R is sent to the comparison circuit 15 and compared with a flow path resistance value R ₀ preset in the reference signal source 14. The flow path resistance value preset in the reference signal source 14 is a flow path resistance value calculated by measuring the initial pressure, drainage time, and the like at a normal time when the drainage pipe and the like are clean.

If the difference between the flow path resistance R obtained by the comparison circuit 15 and the reference value R ₀ exceeds a predetermined allowable range, the comparison circuit 15 determines that there is an abnormality and sends an alarm signal to the control circuit 16. Based on the alarm signal from the comparison circuit 15, the control circuit 16 issues an alarm or stops the cleaning mechanism.

[0018]

As described above in detail, according to the present invention, when draining, the flow path resistance value of the drainage system is calculated and obtained, and the calculated result is compared with a predetermined numerical value, whereby the nozzle is operated. Judgment is made as to whether or not it is clogged, and if it is judged that it is clogged, an alarm is generated and the cleaning mechanism is stopped. As a result, a reagent solution or a sample for the next analysis is not injected and analyzed while a part of the reaction solution or the washing solution remains in the reaction container, and the analysis value is not reliable. The problem of having disappeared.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing the operation of the apparatus according to one embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of a conventional device.

[Explanation of symbols]

 1: Reaction vessel 2: Decompression trap 3: Decompression pump 4: Nozzle 5: Exhaust pipe 6: On-off valve 7: Pressure gauge 8: Sampling circuit 9: Differentiating circuit 10: Time measuring circuit 11: Timing circuit 12: Storage unit 13: Arithmetic circuit 14: Reference signal source 15: Comparison circuit 16: Control circuit

Claims (1)

(57) [Claims] 1. An automatic chemical analyzer in which a nozzle is inserted into a container, and the liquid in the container is sucked into a decompression trap by a decompression pump and drained, and the pressure in a flow path between the nozzle and the decompression trap is measured. Flow path of the drainage system from a pressure gauge for performing, a liquid amount in the container, an initial pressure value at the time of drainage of the liquid in the container obtained from the pressure gauge, and a drainage time obtained from a pressure fluctuation during drainage. An automatic chemical analyzer comprising: a calculating means for obtaining a resistance value; and a comparing means for comparing a result calculated by the calculating means with a predetermined numerical value.