How to install PPM index in production. We are struggling with quality. Is there a need for a systematic definition of pH

Product defects express equally often both in percentage ratio and in relation to a million samples produced. You can argue about the advantages and minuses of one or another method of expression. In his practice, I most often use the expression of defectiveness in relation to a million samples and consider it more convenient. However, the calculation methods considered in this article can easily be transferred to the percentage.

Product defects are a characteristic describing the amount of defective samples in a batch or a certain amount of samples produced. In this case, we will use PPM (Parts Per Million) - the number of defective samples relative to the millions of manufactured.

Ppm \u003d number of defective samples / millions made samples

The indicator 2500 ppm means that among the millions of manufactured products 2500 may be defective.

The meaning is to determine how many defective samples we get in the manufacture of 1 million products. It should be paid to the fact that we are not talking about defects, but about defective samples. Those. The calculation takes into account not the number of defects, but the number of products containing at least one defect. Each defective sample may contain an unlimited number of defects, and however, it is precisely the number of samples into account.

To calculate the indicator, it is no need to expect a moment when a million products are produced. When calculating, any number of observed products can be accepted. In this case, the calculation formula will acquire the following form:

Ppm \u003d (number of defective samples / number of samples produced) 1 000 000

For example, 750 products were produced, 36 of which did not pass quality control - turned out to be defective. In this way:

Ppm \u003d (36/750) 1 000 000 \u003d 48 000

Using PPM for quality assessment in selective control

When using a metric for accounting for selective control results, the question rises to what to relate the number of found defective samples is to the sample size or part of the party?

The number of defective samples found in the sample is compared with the estimated number, on the basis of which the conclusion is made on the suitability or unsuitability, acceptance or not accepting the entire party. In the event that, according to the results of control, the party is accepted, the number of defects is compared with the number of products in the party. If the battery is blocked - the number of defects is compared with the sample size. After sorting the batch, the total number of found defective samples is compared to the number of proven products. The calculation formulas are shown below:

• For the received party:
  Ppm \u003d (number of defective samples / party size) 1 000 000
• For a rejected party:
  Ppm \u003d (number of defective samples / sample size) 1 000 000
• For a batch of products after sorting:
  Ppm \u003d (number of defective samples / number of proven samples) 1 000 000

The last formula is also used for multi-level selective control. For example, selectively verified by a batch of 1000 samples. Sample size - 50 samples. Found 2 defective samples, which is within the tolerance for this case. The calculation is carried out as follows:

Ppm \u003d (2/1 000) 1 000 000 \u003d 2 000 ppm

If the battery was rejected (2 defective samples of 50 - not permissible), the calculation is carried out as follows:

Ppm \u003d (2/50) 1 000 000 \u003d 40 000 ppm

The rejected party succumbed to 100% inspection, resulting in another 37 more defective products. Thus, the final result is as follows:

Ppm \u003d [(2 + 37) / 1 000] 1 000 000 \u003d 39 000 ppm

Instead of the PPM indicator, it is sometimes used by DPM (Defects Per Million) - the number of defects per million products. Despite the fact that both indicators may display the same value - the number of defective samples in a million products - should be distinguished and used for various purposes. DPM, as an indicator of the number of defects in a million samples, is definitely less than PPM, but can tell about the process much more.

The idea of \u200b\u200bwriting this article happened by chance when in the company where I work, a device that measures the degree of pollution of water appeared. The device has become so popular among the team that everything was measured, which has a liquid state.

After a number of such measurements, I decided in more detail, in a relaxed atmosphere to conduct "tests" of water, which you have to drink at home. After all, it is no secret that water is almost 2/3 masses of a person's body, and on what water we use, our health with you depends.

The device that will be discussed today belongs to TDS meters. Chinese manufacturers have long copied all possible technologies, and assume that in the Russian market you can find a Chinese analogue of any instrument.

The view of the unparalleled, similar to an electronic thermometer, the TDS device is designed to measure the mineralization of water. Speaking with a simple and accessible language, this device measures the content of salts in water.

Detailed features of the device are presented in a summary table:

Whatever unfamiliar words did not take the characteristics of TDS, all that is needed to test water, these are numbers on the built-in screen.

Table of "pollution" of water. **
ValueTDS.-Mimeter (ppm.)	Description of value
	Ideal drinking water (multi-level cleaning)
From 51 to 169	Acceptable for drinking (usually after household filters)
	Heavy water
From 171 to 300	Water on the verge of permissible
From 300 to 500	Unpleasant and unacceptable for making tea
	Dangerous to health
** - These figures do not apply to special therapeutic and mineral waters.

I am confident that most of our readers have at home there are filters like "barrier", "aquaphor" or reverse osmosis. How they purify water, and is available to drink purified water, interests many. In today's article, we will look at how cleaning the water filter "Barrier". In addition, especially for this article was acquired bottles with drinking water of various brands in one of Samara's shops, and they will also take our "test."

Immediately I would like to place all the points over "I".

The first test was undergoing conventional water from under the tap. The house in which the domestic water pipes did not change 24 years, clearly stored in themselves if not "bacteriological weapons", then the sand and salts in them abound.

As you can see, if we compare the resulting result with the water pollution table, then the water from the tap is almost on the verge of permissible values. I think no one risks drinking such water without passing it through the filter.

The filter is a separate topic. I am sure that many, having bought a household filter, the first months clearly followed the schedule for changing the cleaning cartridge, but then changed it from the case towards the case.

I am not an exception, there was a time when the cartridge worked on the recommended time a couple more three months. What we drank, and that we were settled in our kidneys, they will show years. This time, the first tests of the filter "Barrier" were conducted on the filter, which was supposed to be replaced a month ago.

Hornly! Water that has been cleaned by the "barrier" with an overdue cartridge is significantly worse than tap water! I think now many have thought about when the last time I was filter cartridge. The instructive figures became a step towards the fact that the changeable cassette was replaced by a new one and the date of its next replacement. I am confident that now after such readings, the replacement of the cartridge will be held on time.

To be honest, the numbers that Soleman showed me, struck me. If we consider that this water drank a small daughter, it remains only hopes that it will not affect her health.

The next measurement of water was made with the new cartridge already installed. The resulting result is though on the verge, but is in the range of clean water, which has been cleaned in the household filter.

Everyone knows that by installing a new cartridge, you need to merge two water jugs. We measured every drain of water, and the numbers were unchanged.

Analyzing the data obtained, it should be understood that therapeutic mineral waters used by special recipes significantly exceed the permissible values \u200b\u200bof water mineralization.

Name	Characteristic	Obtained value (ppm)	Price, rub.)
	"Water for children", from the artesian well. Negasted. Tu-0131-007-29061494-05 with meas. №1.2. Common mineralization from 200 to 500 mg / l.
"Palace"	Mineral water drinking dining water. Negasted. General mineralization from 0.3 to 0.6 g / dm 3
	Natural drinking water. Mineralization from 0.3 to 0.75 g / l.
"Volzhanka"	"Undora". Mineral water. Therapeutic and dining room natural. Common mineralization from 0.8 to 1.2 g / dm 3.
	Pure non-carbonated drinking water. Mineralization of no more than 250 mg / l.
"Aqua Mineral" *	Pure drinking water. Non-carbonated artesian purified first category. Common mineralization from 50 to 500 mg / l.
	Structured. Tu-0131-004-58526959-09. Mineralization of no more than 1000 mg / l.

* - Now I personally, with an equal basis, choose this brand of water.

For those who are difficult to transfer PPM units to understandable values, remind you that 1 ppm corresponds to 1 mg / liter.

If I understood everything correctly and followed the fact that the device is working (not a fact), then the water of most manufacturers does not reach the minimum border to the label of the mineralization.

What kind of water to buy and drink, this is your choice, but I would like to have a similar device in each house, which could identify the pollution of water in time. Agree, because it would be useful once a week to check water from under the household filter. Perhaps the flow of water in your family is much higher than the calculated one, and the cartridge at the end of its term has not been filtered, but source of salt.

How much is the TDS Slemer? At first glance, the price range for this device does not even determine. However, after conducting a small monitoring of online stores, a near-time difference in the price of various sites was revealed. The price ranges from 600 to 1350 rubles.

For anyone who wishes to purchase this device, we found, perhaps the most cheap price on the TDS device. The online store DC.com offers a whole range of sollemors, and the price of them starts from $ 11.40. Transferring this amount to the price-understandable Russians, it turns out just over 350 rubles.

Ordering the goods in the online store, remember that you will have to pay for delivery.

So our test filter "Barrier" and a number of mineral and drinking water approached the end. I am convinced that professionals working in laboratories will consider this "test" for amateur. Let the numbers obtained as a result of the test relative, the main thing is to everyone it becomes clear that the cartridges in household filters need more often!

The article would not be complete, if, analyzing 7 stamps of drinking water for mineralization, we would not tell what kind of waters cheaper. Our site often publishes data on the price analysis of consumer goods and products. Now the time has come for drinking water.

Name

Bottle volume (l.)

Price per bottle (rub.)

Price for 1 liter (rub.)

(ppm). To transfer MS / CM measurement units to PPM and back, you need to determine which coefficient of recalculation must be used. As a rule, TDS meters use the coefficients 0.5, 0.64 or 0.7. Less often apply 1.0. Sometimes the device has a function of manual input of this coefficient.

EC-meter		TDS-meter
(mSM / See)	(μm / see)	0.5 ppm.	0.64 ppm.	0.70 ppm.
0.1	100	50 ppm.	64 ppm.	70 ppm.
0.2	200	100 ppm.	128 ppm.	140 ppm.
0.3	300	150 ppm.	192 ppm.	210 ppm.
0.4	400	200 ppm.	256 ppm.	280 ppm.
0.5	500	250 ppm.	320 ppm.	350 ppm.
0.6	600	300 ppm.	384 ppm.	420 ppm.
0.7	700	350 ppm.	448 ppm.	490 ppm.
0.8	800	400 ppm.	512 ppm.	560 ppm.
0.9	900	450 ppm.	576 ppm.	630 ppm.
1.0	1000	500 ppm.	640 ppm.	700 ppm.
1.1	1100	550 ppm.	704 PPM.	770 ppm.
1.2	1200	600 ppm.	768 ppm.	840 ppm.
1.3	1300	650 ppm.	832 ppm.	910 ppm.
1.4	1400	700 ppm.	896 ppm.	980 ppm.
1.5	1500	750 ppm.	960 ppm.	1050 ppm.
1.6	1600	800 ppm.	1024 ppm.	1120 ppm.
1.7	1700	850 ppm.	1088 ppm.	1190 ppm.
1.8	1800	900 ppm.	1152 ppm.	1260 PPM.
1.9	1900	950 ppm.	1216 ppm.	1330 ppm.
2.0	2000	1000 ppm.	1280 ppm.	1400 ppm.
2.1	2100	1050 ppm.	1334 ppm.	1470 PPM.
2.2	2200	1100 ppm.	1408 ppm.	1540 ppm.
2.3	2300	1150 ppm.	1472 ppm.	1610 ppm.
2.4	2400	1200 ppm.	1536 ppm.	1680 ppm.
2.5	2500	1250 PPM.	1600 ppm.	1750 ppm.
2.6	2600	1300 ppm.	1664 ppm.	1820 ppm.
2.7	2700	1350 ppm.	1728 ppm.	1890 ppm.
2.8	2800	1400 ppm.	1792 ppm.	1960 ppm.
2.9	2900	1450 ppm.	1856 ppm.	2030 PPM.
3.0	3000	1500 ppm.	1920 ppm.	2100 ppm.
3.1	3100	1550 PPM.	1984 PPM.	2170 ppm.
3.2	3200	1600 ppm.	2048 ppm.	2240 ppm.

* Note: 1 MS / CM \u003d 1000 μS / CM

The coefficient of various devices

Manufacturer or device	Coefficient
,	0.5
	0.64
	0.70
	1.00

How to translate TDS (PPM) units in EC (MS / CM) independently

To translate EC measurement units ( μm / see) In TDS (PPM), it is necessary to iMM / cm multiply on the TDS-meter coefficient (0.5, 0.7 or another).

To translate TDS (PPM) measurement units in EC ( μm / see) It is necessary to divide the measured value to the TDS meter coefficient (0.5, 0.7 or other).

How to determine the TDS-meter conversion factor

The TDS-meter conversion factor can be defined in the case if the device is both an EC meter. In such cases, for the same solution, it is necessary to measure the testimony of mineralization (PPM) and electrical conductivity (ICM / cm). Next, we divide the value of mineralization (PPM) on the value of electrical conductivity (IMM / cm). The resulting number is the coefficient for converting this TDS meter.

• Ppmv (PER Million by Volume) is a concentration unit in million dollars. Those. The ratio of the volume fraction of everything (including this share). Naturally, for small concentration values, this value is equal to the ratio of the volume fraction of everything else without taking into account this share.
• ! This is the ratio of the partial pressure of water vapor in the gas mixture to the pressure of the dry mixture. For measurements of small moisture values \u200b\u200bin the gases, this is the most common unit and in 99% of cases it is meant under the mysterious abbreviation Ppm (\u003d ppm).

• PPMW. (Parts Per Million by Weight) is a concentration unit in million dollars(Sometimes they say "by weight"). Those. The ratio of the mass fraction of everything (including this share). Naturally, for small concentration values, this value is equal to the ratio of the weight fraction to the rest without taking into account this share.
  • lim X → 0 (x / (1-x): 1 / x) \u003d 1, i.e. at x → 0 ratio x / (1-x) → x;
• ! With regard to moisture, this is the ratio of the mass of water vapor in the gas mixture, to the mass of a dry gas mixture.

• Similarly: PPB (Parts Per Billion)- This is a unit of concentration in billion dollars \u003d parts per billion. Consider there :)

How to translate ppm to mg / l?

• For solutions of something there in water at 1 ppm w \u003d 1 mg / l
• For all other cases, keep in mind that mg. - this is, and l.-. Get careful there, cross the hedgehog and horns!
• Above there are all the necessary data for translation :)

Note that in most cases, an uncertain unit "PPM" - for gas mixtures it is PPMV, and for solutions and dry mixtures it is PPMW, although it is often a desire to put a bruise for the author's eye of the text that used such a unit for equity ratings without reservation. Be careful, because when the definition error, you can not even fall into order a reliable value.

For analysis of mixtures of various gases In order to determine their qualitative and quantitative composition, enjoy the following the main units of measure:
- "mg / m 3";
- "ppm" or "ppm";
- "% about. d. ";
- "% NKPR".

The mass concentration of toxic substances and the maximum permissible concentration (MPC) combustible gases is measured in MG / M 3.
The unit of measurement "mg / m 3" (eng. "Mass Concentration") is used in the designation of the concentration of the measured substance in the air of the working area, the atmosphere, as well as in the exhaust gases, expressed in milligrams on the cubic meter.
When performing gas analysis, as a rule, end users often translate gase concentration values \u200b\u200bfrom PPM in MG / M 3 and vice versa. This can be done using our calculator values \u200b\u200bof the units of gases.

The million-like proportion of gases and various substances is relative and designated in PPM or PM.
"PPM" (English "Parts Per Million" - "parts per million") - a unit of measuring the concentration of gases and other relative values, similar to the meaning of ppm and percentage.
The PPM unit (PM) is conveniently used to assess low concentrations. One millionth share is one part per 100,00000 parts and has a value of 1 × 10 -6 from the base indicator.

The most common unit of measuring the concentrations of combustible substances in the air of the working area, as well as oxygen and carbon dioxide is the volume fraction, which is denoted by the reduction of "% about. d. " .
"% About. d. " - is the value equal to the ratio of the volume of any substance in the gas mixture to the volume of the entire gas sample. The volume fraction of gas is customary to express in percent (%).

"% NKPR" (LEL - English Low Explosion Level) - lower concentration limit of flame distribution, the minimum concentration of the fuel explosive substance in a homogeneous mixture with an oxidative medium at which an explosion is possible.