JP6052551B2 - Method for measuring the weight concentration of particulate matter in the air - Google Patents

Description

  The present invention relates to a method for measuring the weight concentration of particulate matter in the air.

A highly pharmacologically active drug is a drug that has a strong medicinal effect on the human body in a small amount, typified by anticancer drugs and hormone drugs. For example, there is a highly pharmacologically active pharmaceutical agent that brings some physiological activity to the human body at an air concentration of 1 μg / m ³ or less. In such drug handling facilities, the prevention of scattering of pharmaceutical powders in manufacturing equipment and equipment (pharmaceutical powders) from the viewpoints of product quality control (preventing contamination), preventing health hazards to workers, and preventing environmental pollution. (Containment of body) measures are important. In general, work is performed in a physically enclosed containment device such as an isolator. However, there are demands for cost reduction and flexible production systems for pharmaceutical manufacturing, and there is a high need for handling pharmaceutical powders in semi-open facilities (semi-enclosed facilities) such as clean booths.

The British Occupational Safety and Health Act (COSH) provides guidelines for powder containment, in which the risk of pharmaceuticals is classified into four to six categories called OEL (Occupational Exposure Limit). Classification and appropriate containment equipment (equipment) specifications are defined for each category. This OEL is classified based on the air concentration μg / m ³ of the pharmaceutical powder (dust) scattered during handling (see Non-Patent Document 1). In order to verify that a powder handling facility (equipment) meets the specifications stipulated in this guideline, the concentration of pharmaceutical powder scattered in the powder handling facility etc. in the air μg / m It is essential to actually measure ³ and compare it to the OEL acceptable exposure control.

  When the airborne concentration of the scattered pharmaceutical powder is grasped, and the evaluation of the scattering property and containment of the pharmaceutical powder is performed, the use of the drug with high pharmacological activity itself may adversely affect the worker due to adhesion to the skin or suction. There is a concern that For this reason, the scattered state is often evaluated using a highly safe simulated powder instead of using the pharmaceutical powder.

  In Non-Patent Document 2, the SMEPAC method (The Standardized Measurement of Equipment Particulate Airborne Concentration method) using lactose powder as a simulated powder is recommended. The lactose used here is a substance used as a pharmaceutical excipient, is harmless to the human body, easily dissolved in water, and has a good stability, and is widely used. However, in order to quantitatively analyze the lactose powder dispersed in the facility to be measured, an expensive and large-scale apparatus and complicated work are required. Specifically, the lactose powder scattered in the measurement target facility is sampled by a filter or wiping, transported to the analysis facility, and analyzed and evaluated by a device such as a high performance liquid chromatograph or ion chromatograph. Things have been done. For this reason, it often takes about several days to a week to obtain the result, and it is difficult to perform the evaluation in a short time in the facility to be measured.

On the other hand, if a particle counter is used, the number concentration (particles / m ³ ) of air particles can be easily measured in real time on the spot, but the particle weight cannot be measured in principle. Usually, since the weight of the scattered individual particles is non-uniform, it cannot be calculated from the formula of the number concentration of air particles = the weight of scattered particles × the number concentration. That is, even if only the particle counter is used, there is a problem that the air concentration μg / m ³ of the particulate matter (for example, pharmaceutical powder) in the measurement target space cannot be obtained directly.

Written by Kazuhiro Shima, Containment Technology, Chemical Equipment, 7, pp. 63-73 (2009) ISPE (The International Society for Pharmaceutical Engineering Inc.) Good Practice Guide Guidelines for evaluating the containment performance of pharmaceutical equipment, edited by SMEPAC Committee, ISBN 1-931879-51-6

  In view of the above circumstances, the present invention provides a method for easily measuring the weight concentration (air concentration) of particulate matter such as pharmaceutical powders scattered in a measurement target space.

In order to achieve the above object, the present invention provides the following means.
The airborne particulate matter weight concentration measuring method of the present invention is a particulate matter weight concentration measuring method scattered in a measurement target space,
_A first step of introducing a gas sample S ₀ in the measurement target space into a first vibrator sensor and obtaining a change amount ΔF _A of a vibration frequency of the sensor portion;
Said gaseous sample S ₀ in the measurement target space through the particulate filter, to obtain a gas sample S ₁ obtained by removing the particulate matter, by introducing the gaseous sample S ₁ to the second transducer sensor, A second step for obtaining a change amount ΔF _B of the vibration frequency of the sensor unit;
The gaseous sample S ₀ in the measurement target space is passed through a particulate matter removal filter and a gaseous matter removal filter that removes the gaseous matter, thereby obtaining a gaseous sample S _{2 from} which the particulate matter and the gaseous matter have been removed. Te, a third step of the gaseous sample S ₂ is introduced into the third transducer sensor, obtains the variation △ F _C of the vibration frequency of the sensor unit,
A change amount ΔF of the vibration frequency of the first vibrator sensor due to the particulate matter scattered in the measurement target space is calculated from an equation: ΔF = ΔF _A −ΔF _B −ΔF _c With four steps,
Based on the known calibration curve indicating the relationship between the weight of the substance adhering to the first vibrator sensor and the amount of change in frequency, from the change ΔF obtained in the fourth step, the first vibrator sensor A fifth step for determining the weight M of the adhering particulate matter,
Further, in the first step, the number concentration N _{1 of} the particulate matter in the gas sample S ₀ having the volume V ₀ introduced into the first vibrator sensor and the gas sample S ₀ are used as the first vibrator. The number concentration N ₂ of the particulate matter in the exhaust gas S ₀ ′ after introduction into the sensor is measured with a particle counter, and the following formula (1)
X = M × {N ₁ / (N ₁ −N ₂ )} / V ₀ (1)
By, and having a, a sixth step of calculating the weight concentration X of the particulate matter contained in the gas sample S _0.

In weight concentration measuring method of the air particulate matter of the present invention, through the gas sample S ₀ in the measurement target space into the particulate filter and the gaseous substances removing filter, said particulate matter and said A gas sample S ₂ from which gaseous substances have been removed is obtained, and the gas sample S ₂ is introduced into the first vibrator sensor, the second vibrator sensor, and the third vibrator sensor, and the vibration frequency of each sensor unit is obtained. The preliminary steps for _obtaining the respective reference values F _AS , F _BS and F _CS are performed in advance before the first to third steps. It is preferable to obtain the change amounts ΔF _A , ΔF _B and ΔF _c by subtracting a reference value.

In the weight concentration measurement method for particulate matter in the air according to the present invention, the weight M _{1 of the} particulate matter attached to the first vibrator sensor in the initial state of the space to be measured by the first to fifth steps. In the state where the powder particles are scattered in the measurement object space, the weight M _{2 of the} particulate matter adhered to the first vibrator sensor is obtained by the first to fifth steps, and the first In the six steps, it is preferable to obtain the weight concentration X of the particulate matter obtained by calculating M = M ₂ −M ₁ as the weight concentration of the powder particles scattered in the measurement target space.

  In the method for measuring the weight concentration of particulate matter in the air according to the present invention, the air flow of any one of the gas samples is applied to the flat sensor portion of the first to third vibrator sensors at an elevation angle of 35 to 75 degrees and / or a depression angle. It is preferable to spray from a position of 35 to 75 degrees.

  According to the method for measuring the weight concentration of particulate matter in the air according to the present invention, the weight concentration of particulate matter such as pharmaceutical powder scattered in the measurement target space can be easily measured at the measurement site. At this time, since the influence of chemical substances other than the particulate matter scattered in the measurement target space on the measurement result can be almost eliminated, a highly reliable measurement result with high reliability can be obtained.

It is a conceptual diagram of the measuring apparatus used by embodiment of this invention. FIG. 3 is a schematic cross-sectional view of the measuring device 20 as viewed from the side of the flat plate vibrator sensor 1 provided in the measuring device 20 used in the embodiment of the present invention. The result of having simulated the flow velocity of the gas sample around vibrator sensor 1 is shown.

  Hereinafter, the present invention will be described based on preferred embodiments.

The airborne particulate matter weight concentration measurement method of the present embodiment has the following first to sixth steps.
The vibrator sensor used in each step is not particularly limited as long as it has a function of changing the vibration frequency (resonance frequency) of the vibrator by adsorbing a substance on the surface of the vibrator. Examples thereof include a crystal resonator sensor (QCM sensor) and a ceramic resonator sensor. The vibration characteristics of the plurality of vibrators used for measurement are preferably the same. Usually, a QCM sensor is preferable to a ceramic vibrator sensor because a highly accurate measurement result can be obtained.

  The measuring device used in this embodiment includes a first vibrator sensor, a second vibrator sensor, and a third vibrator sensor. As such a measuring apparatus, for example, three independent casings are provided, one transducer sensor is arranged in each casing, and a different filter is provided in each of the intake portions of these three casings. One measuring device is mentioned. Note that all the three transducer sensors may not be arranged together in a single measuring device. For example, a measurement method in which three independent measurement devices including one transducer sensor are prepared, different filters are provided in the intake section of each measurement device, and the three independent measurement devices are used in parallel is also mentioned. .

  FIG. 1 shows a conceptual diagram of a measuring apparatus used in this embodiment. In the measuring apparatus 10 of FIG. 1, a QCM sensor 1 is disposed in a casing 2. The QCM sensor 1 is connected to a power source 6 outside the casing 2, a frequency counter 7, and a data processing computer (PC) 8. The gas sample S to be used for measurement is introduced into the casing from the intake section 3 provided in the casing 2 and guided to the sensor section of the QCM sensor 1, and then exhausted from the exhaust section 5 provided in the casing 2. As discharged. For example, a suction pump is connected to the exhaust unit 5.

The intake portion 3 of the casing 2 has a known configuration in which a particulate matter removal filter and / or a gaseous matter removal filter (filter 4) can be attached and detached as necessary.
As the particulate matter removal filter, a known filter that can remove a solid substance contained in the gas sample S and having a volume that can be attached to the QCM sensor is applicable. An example of such a filter is a HEPA filter.
Gaseous substance removal filter removes gaseous substances that are contained in gas sample S and can be attached to the QCM sensor, that is, molecular contaminants that are smaller than particulate substances and are difficult to remove with particulate matter removal filters. A known chemical filter that can be used is applicable.

<First step>
In the first step, the gas sample S ₀ in the measurement target space is introduced into the first vibrator sensor, and the variation ΔF _A of the vibration frequency of the sensor unit is obtained.
It is assumed that the gaseous sample S ₀ contains particulate matter and gaseous matter. When a predetermined amount (volume V ₀ ) of the gas sample S ₀ comes into contact with the sensor portion of the first vibrator sensor, the particulate matter and the gaseous matter adhere to the sensor portion, resulting in vibration of the first vibrator sensor. The frequency changes. From the vibration frequency after the introduction of the gaseous sample S _0, by subtracting the vibration frequency before the introduction of the gaseous sample S _0, the purpose of the variation △ F _A is determined.

Further, in the first step, the number concentration N ₁ of the particulate matter in the gas sample S ₀ having the volume V ₀ introduced into the sensor unit of the first vibrator sensor and the gas sample S ₀ are used as the first vibrator sensor. The number concentration N ₂ of the particulate matter in the exhaust gas S ₀ ′ after being introduced to is measured with a particle counter.

  As the particle counter used here, a known device capable of detecting the particulate matter to be measured can be applied. Although the installation location of the particle counter is not particularly limited, it is preferable to install the particle counter immediately before the intake portion 3 and immediately after the exhaust portion 5 of the measuring apparatus 10 from the viewpoint of improving measurement accuracy.

<Second step>
In a second step, the gas sample S ₀ in the measurement target space through the particulate filter, to obtain a gas sample S ₁ removing the particulate matter, the gas sample S ₁ to the second transducer sensor Then, the change amount ΔF _B of the vibration frequency of the sensor unit is obtained.
By gas sample S ₁ of a predetermined amount is brought into contact with the sensor portion of the second transducer sensor, a result of the gaseous substance is adhered to the sensor section, the vibration frequency of the second oscillator sensor is changed. From the vibration frequency after the introduction of the gaseous sample S _1, by subtracting the vibration frequency before the introduction of the gaseous sample S _1, it is required variation △ F _B of interest.

<Third step>
In the third step, the gas sample S ₀ in the measurement target space is passed through the particulate matter removal filter and the gaseous matter removal filter to obtain the gas sample S ₂ from which the particulate matter and the gaseous matter have been removed, and the gas samples S ₂ is introduced into the third transducer sensor, we obtain the variation △ F _C of the vibration frequency of the sensor unit.
By gas sample S ₂ of a predetermined amount is brought into contact with the sensor portion of the third transducer sensor, a result of substances which can not be removed by the particulate filter and chemical filter (or other substance) is attached to the sensor unit, the third The vibration frequency of the vibrator sensor may change. From the vibration frequency after the introduction of the gaseous sample S _2, by subtracting the vibration frequency before the introduction of the gaseous sample S _2, the purpose of the variation △ F _C is obtained.

Incidentally, the gaseous sample S ₂ is because it passes through the two filters mentioned above, typically, material is not included so as to adhere to the sensor portion of the third transducer sensor. Therefore, usually, the amount of change △ F _C indicates a value close to 0 (zero).

<Order of first to third steps>
The order in which the first step, the second step, and the third step are performed is not particularly limited, and the three steps may be performed in parallel, or each step may be performed in an arbitrary order.

<Fourth step>
After the first to third steps are completed, the fourth step is performed.
In the fourth step, the change amount ΔF of the vibration frequency of the first vibrator due to the particulate matter scattered in the measurement target space is calculated from the equation: ΔF = ΔF _A −ΔF _B −ΔF _c To do.
The amount of change ΔF reflects only the amount of particulate matter deposited, excluding the gaseous matter and the other materials, among the materials attached to the sensor portion of the first vibrator.

<Fifth step>
In the fifth step, based on the known calibration curve indicating the relationship between the weight of the substance attached to the first vibrator sensor and the amount of change in frequency, the first vibrator sensor is obtained from the change amount ΔF obtained in the fourth step. The weight M of the particulate matter adhering to the sensor part is obtained.
Usually, the relationship is directly proportional. That is, as the change amount ΔF of the first vibrator sensor is larger, the weight M of the particulate matter adhering to the sensor portion of the first vibrator sensor also increases in proportion. The calibration curve may be prepared in advance by a known method.
The weight M which is obtained here is a weight of the particulate matter deposited on the sensor unit, not the total weight of all the particulate matter contained in the gas sample S ₀ of a predetermined amount.

<Sixth Step>
In the sixth step, the following formula (1)
X = M × {N ₁ / (N ₁ −N ₂ )} / V ₀ (1)
By calculating the weight concentration X of particulate matter contained in the gas sample S _0.

As understood from the above formula (1), in this embodiment, the weight M of the particulate matter adhering to the sensor portion of the first vibrator, the particles in the gas sample before and after being introduced into the sensor portion. number concentration N ₁ of Jo _material, N _2, and by measuring the volume V ₀ which gaseous samples S _0, the weight concentration X of the total particulate matter contained in the gas sample S _0, conveniently calculated in the measurement site be able to.

<Preliminary steps>
In this embodiment, the gas sample S ₀ in the measurement target space is passed through the particulate matter removal filter and the gaseous matter removal filter to obtain the gas sample S ₂ from which the particulate matter and the gaseous matter are removed, the gaseous sample S ₂ first transducer sensor, preliminary step of introducing the second transducer sensor and the third transducer sensor, obtains the reference value F _AS oscillation frequency of each sensor _unit, F _BS and F _CS, the Is performed in advance before the first step to the third step, and in the first step to the third step, ΔF _A and ΔF _B are obtained by subtracting each reference value obtained in advance from the actual measurement value of each transducer sensor. And ΔF _c are preferably determined.

  By obtaining the reference vibration frequency when each sensor unit is stable in the preliminary step, the amount of change in the vibration frequency of each sensor unit that occurs during measurement of the actual gas sample in the first to third steps can be obtained more accurately. be able to.

<Measurement method when the simulated powder is scattered in the space to be measured>
In the present embodiment, first, the first step to the fifth step are performed in the initial state of the measurement target space to obtain the weight M _{1 of the} particulate matter attached to the first vibrator sensor, and then the measurement is performed. In a state where powder particles (for example, simulated powder) are scattered in the target space, the weight M _{2 of the} particulate matter attached to the first vibrator sensor is obtained by performing the first step to the fifth step, and then In the sixth step, the weight concentration X of the particulate matter obtained by calculating M = M ₂ −M ₁ may be obtained as the weight concentration of the powder particles scattered in the measurement target space.

For both the initial state in which the powder particles are not scattered and the state in which the powder particles are scattered, the first step to the fifth step are performed, and the minute substances (floating particles, microorganisms, etc.) floating in the initial state the weight M ₁ of the particulate matter, by subtracting from the weight M ₂ of the particulate matter comprising the powder particles in a state in which the powder particles are scattered, by reducing the effects of fine particulate matter floating in the initial state, the purpose The weight concentration of the powder particles can be determined more accurately.
At this time, the measurement of the particle counter in the sixth step does not need to be performed in the initial state, and is performed only in a state where the powder particles are scattered, so that the measurement efficiency is excellent.

  The method for scattering powder particles such as simulated powder in the measurement target space is not particularly limited. For example, the simulated powder is scattered by putting the simulated powder in a rotary drum and rotating, and the simulated powder is discharged from the hopper. A known method such as a method of discharging and further blowing an air blow can be applied. The method for scattering the simulated powder may be appropriately selected according to the size and form of the space to be measured.

In the present embodiment, the first to third vibrator sensors used for obtaining the weight M ₁ and the first to third vibrator sensors used for obtaining the weight M ₂ have the same name for convenience. However, a different sensor may be used in practice. Specifically, each sensor used when obtaining the weight M ₁ may be replaced with a new one when obtaining the weight M ₂ . In order to clarify that the sensor is to be replaced with a new one, the “first to third vibrator sensors” used when obtaining the weight M ₂ may be read as “fourth to sixth vibrator sensors”. .

<An angle at which a gas sample is sprayed onto the sensor>
In the present embodiment, the airflow of any one of the above gas samples is blown from the position of the elevation angle of 35 to 75 degrees and / or the depression angle of 35 to 75 degrees on the flat sensor portions of the first to third vibrator sensors. preferable.

  A specific example will be described with reference to FIG. FIG. 2 is a schematic cross-sectional view of the measuring device 20 as viewed from the side of the flat plate (disc-shaped) transducer sensor 1 provided in the measuring device 20. The same components as those of the measurement apparatus 10 in FIG. 1 are denoted by the same reference numerals, and the description thereof is omitted.

  FIG. 2 shows 0.6 L from a nozzle having a diameter (inner diameter) of 2 mm installed at two positions of an elevation angle of 45 degrees and a depression angle of 45 degrees with reference to the plane of the flat sensor portion of the transducer sensor 1. A state in which the gas sample S is sprayed at a flow rate of at least / min is shown. In FIG. 2, the shading in the casing 2 indicates the result of simulating the speed of the airflow in the casing 2. The dark region is a region where the flow velocity (wind speed) is fast. It can be seen that the air flow of the gas sample is concentrated on both sides of the transducer sensor 1 and efficiently flows.

  The angle at which the air flow of the gas sample is blown onto the flat plate sensor parts (electrode chips) constituting each vibrator sensor affects the probability that the particulate matter contained in the gas sample is captured by the sensor part. From the result of the simulation, the probability that the sensor unit captures the particulate matter is further increased by spraying the air flow of the gas sample on the flat sensor unit from the position of the elevation angle of 35 to 75 degrees and / or the depression angle of 35 to 75 degrees. While further improving, the measurement of the vibrating sensor unit can be stably maintained.

<About OEL of pharmaceutical powder>
The permissible exposure control amount (OEL) of a pharmaceutical having a particularly high pharmacological activity is usually 1 μg / m ³ or less. The method for measuring the weight concentration of particulate matter in the air according to this embodiment can be applied to the evaluation of facilities (apparatus, equipment) that handle such powders of highly pharmacologically active pharmaceuticals.

  A measuring apparatus provided with three QCM sensors (manufactured by Tama Device Co., Ltd.) having a sensor chip with an electrode diameter of 0.5 cm was used. When a 1.1 ng substance adheres to the sensor chip on this disk, it is observed as a frequency change amount of 1 Hz.

  A gas sample was supplied to the first to third QCM sensors of this measuring apparatus at a flow rate of 1 liter / min.

First, powder particles (simulated powder) were scattered in a highly clean space by a known method. To obtain a gas sample S ₂ through the air in the measurement target space into the chemical filter and HEPA filter. The gaseous sample _{S 2} is supplied to the first to third QCM sensor, wait until the sensor unit is stabilized, a primary frequency (frequency of the _background) F _{AS, F BS} and _{F CS,} were respectively obtained.

Next, the third QCM sensor, the gas sample S ₂ is supplied for one minute, to measure the variation of the vibration frequency, to obtain a △ F _C minus the F _CS from the measured values. On the other hand, the second QCM sensor, not through the HEPA filter, the gaseous sample S ₁ through only chemical filter is supplied for one minute, to measure the variation of the vibration frequency, the F _BS from the measured values It was obtained by subtracting the △ _{F B.} The first QCM sensor is supplied with a gas sample S ₀ (the air) that does not pass through either a HEPA filter or a chemical filter for 1 minute, measures the amount of change in the vibration frequency, and calculates F _AS from the measured value. Subtracted ΔF _A was obtained.

From the measurement result for 1 minute, the change amount ΔF = ΔF _A −ΔF _B −ΔF _c of the first QCM sensor due to the powder particles scattered in the measurement target space was calculated to be 16 Hz. Met. This indicates that 17.6 ng of powder particles adhered to the first QCM sensor chip.

Further, in the measurement for 1 minute, the number concentration of the powder particles contained in the gas sample S ₀ is 4000 / liter, and the powder particles in the exhaust S ₀ ′ after being supplied to the first QCM sensor A number concentration of 3600 / liter was measured using a particle counter. This indicates that 400 powder particles adhered to the first QCM sensor chip.

From the above, the weight concentration of the powder particles contained in the gas sample S ₁ is required to be 17.6 × 4000/400 = 176 ng / liter, that is, 176 μg / m ³ .

  The configurations and combinations thereof in the embodiments described above are examples, and the addition, omission, replacement, and other modifications of the configurations can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Vibrator sensor 2 ... Casing 3 ... Intake part 4 ... Filter 5 ... Exhaust part 6 ... Power supply 7 ... Frequency counter 8 ... PC
10, 20 ... Measuring device S ... Gas sample S '... Exhaust gas

Claims (4)

A method for measuring the weight concentration of particulate matter scattered in a measurement target space,
_A first step of introducing a gas sample S ₀ in the measurement target space into a first vibrator sensor and obtaining a change amount ΔF _A of a vibration frequency of the sensor portion;
Said gaseous sample S ₀ in the measurement target space through the particulate filter, to obtain a gas sample S ₁ obtained by removing the particulate matter, by introducing the gaseous sample S ₁ to the second transducer sensor, A second step for obtaining a change amount ΔF _B of the vibration frequency of the sensor unit;
The gaseous sample S ₀ in the measurement target space is passed through a particulate matter removal filter and a gaseous matter removal filter that removes the gaseous matter, thereby obtaining a gaseous sample S _{2 from} which the particulate matter and the gaseous matter have been removed. Te, a third step of the gaseous sample S ₂ is introduced into the third transducer sensor, obtains the variation △ F _C of the vibration frequency of the sensor unit,
A change amount ΔF of the vibration frequency of the first vibrator sensor due to the particulate matter scattered in the measurement target space is calculated from an equation: ΔF = ΔF _A −ΔF _B −ΔF _c With four steps,
Based on the known calibration curve indicating the relationship between the weight of the substance adhering to the first vibrator sensor and the amount of change in frequency, from the change ΔF obtained in the fourth step, the first vibrator sensor A fifth step for determining the weight M of the adhering particulate matter,
Further, in the first step, the number concentration N _{1 of} the particulate matter in the gas sample S ₀ having the volume V ₀ introduced into the first vibrator sensor and the gas sample S ₀ are used as the first vibrator. The number concentration N ₂ of the particulate matter in the exhaust gas S ₀ ′ after introduction into the sensor is measured with a particle counter, and the following formula (1)
X = M × {N ₁ / (N ₁ −N ₂ )} / V ₀ (1)
By weight A method for measuring the concentration of airborne particulate matter and having a, a sixth step of calculating the weight concentration X of the particulate matter contained in the gas sample S _0. The measurement target the gaseous sample S ₀ in space through the particulate filter and the gaseous substances removing filter, to obtain a gas sample S ₂ removal of the particulate material and the gaseous substance, its the gaseous sample S ₂ the first transducer sensor is introduced into the second transducer sensor and the third transducer sensor, obtains the reference value F _AS oscillation frequency of each sensor _unit, F _BS and F _CS, the A preliminary step is performed in advance before the first to third steps,
2. The change amounts ΔF _A , ΔF _B, and ΔF _c are obtained by subtracting the reference values from measured values of the vibrator sensors in the first to third steps. 4. A method for measuring the weight concentration of particulate matter in air. In the initial state of the measurement target space, after obtaining the weight M _{1 of the} particulate matter attached to the first vibrator sensor by the first to fifth steps,
In a state where powder particles are scattered in the measurement target space, the first to fifth steps determine the weight M _{2 of the} particulate matter attached to the first vibrator sensor,
In the sixth step, the weight concentration X of the particulate matter obtained by calculating M = M ₂ −M ₁ is obtained as the weight concentration of the powder particles scattered in the measurement target space. The weight concentration measuring method of the air particulate matter according to claim 1 or 2.   The airflow of any one of the gas samples is blown from a position of an elevation angle of 35 to 75 degrees and / or a depression angle of 35 to 75 degrees on a flat plate sensor portion of the first to third vibrator sensors. The weight concentration measuring method of the air particulate matter according to any one of 1 to 3.