Таблица перевода единиц измерения давления

Единицы бар мм рт.ст. мм вод.ст. атм (физич.) кгс/м2 кгс/см2 (технич. атм.)
Па кПа Мпа
1 бар 1 750.064 10197,16 0.986923 10.1972 ∙ 103 1,01972 105 100 0.1
1 мм рт.ст. 1.33322 ∙10-3 1 13,5951 1.31579 ∙10-3 13,5951 13.5951 ∙10-3 133.322 133.322 ∙10-3 133.322 ∙10-6
1 мм вод.ст. 98.0665 ∙10-6 73.5561 ∙ 10 -3 1 96.7841 ∙10-6 1 0.1∙10-3 9.80665 9.80665 ∙10-3 9.80665 ∙10-6
1 атм 1.01325 760 10.3323 ∙103 1 10.3323∙ 103 1.03323 101.325 ∙ 103 101.325 101.325 ∙10-3
1 кгс/м2 98,0665 ∙10-6 73.5561 ∙ 10 -3 1 96.7841 ∙10-6 1 0.1∙10-3 9.80665 9.80665 ∙10 -3 9.80665 ∙10-6
1 кгс/см2 0,980665 735.561 10000 0.967841 10000 1 98.0665 ∙ 103 98.0665 98.0665 ∙10-3
1 Па 10 -5 7.50064 ∙10-3 0,1019716 9.86923  ∙10-6 101.972 ∙ 10-3 10.1972 ∙10-6 1 10 -3 10 -6
1 кПа 0.01 7.50064 101,9716 9.86923 ∙10-3 101.972 10.1972 ∙10-3 103 1 10 -3
1 МПа 10 7.50064 ∙103 101971,6 9.86923 101.972 ∙103 10.1972 106 103 1

К системе СИ относятся:                    Инженерные единицы:
Бар

1 бар = 0,1 Мпа                              1 мм рт.ст. = 13.6 мм вод.ст.
1 бар = 10197.16 кгс/м2                  1 мм вод.ст. = 0.0001кгс/см2
1 бар = 10 Н/см2                                      1 мм вод.ст. = 1 кгс/м2
                                                                       1 атм = 101.325 ∙ 10Па
Па

1 Па = 1000МПа
1 МПа = 7500 мм. рт. ст.
1 МПа = 106 Н/м2

The RKMA-P is designed to work in composition of precision electronic transducersPressure sensing quartz crystal sensor RKMA-P. The RKMA-P is designed to work in composition of precision electronic transducers, pressure gauges and pressure controllers with a frequency or digital output signal as a converter of current values of pressure to frequency.

Applications

The RKMA-P is designed to work in composition of precision electronic transducers, pressure gauges and pressure controllers with a frequency or digital output signal as a converter of current values of pressure to frequency.

Device

RKMA-R - manometric sensor, consists of a membrane 3, on which a force-sensitive piezoresonance element in the form of a dual tuning fork of flexural vibrations is rigidly fixed. The piezoelectric element is located in an evacuated cavity formed by the gasket 2 and the cover of the sensor 1. All the details of the resonator are made of single-crystal quartz. Under the action of sensor, the membrane bends, stretching or compressing the force-sensitive piezoelectric element, and the RKMA-P resonance frequency changes due to the pressure-acting conversion function.

Features

  • High resolution and accuracy;
  • Long term quartz crystal stability;
  • Radiation resistance;
  • Low temperature dependence reproducible in a wide range of operating temperatures (-60…+80 °C);
  • Low power consumption;
  • Suitable for precision pressure equipment

A number of RKMA-R, differing in design features and ranges of working pressure is produced.

Electrical characteristics (at normal climatic conditions) / Operating conditions

 

Parameters Specifications and remarks Units

Electrical characteristics

Model of the sensor

RKMA-P-1

RKMA-P-3

RKMA-P-4

RKMA-P-21

 

Frequency Range, fO

40.000…48.000

kHz

Series resistance typ./max., RS

120/ 200

150/ 250

kOhm

Drive level max., DL

4.0

µW

Insulation resistance min., IR

400

MOhm

Motional characteristics

Strait:                                                F(P)=fO +A1*P +A2*P2+ A3*P3,

where: F(P) – sensors’s frequency at current value of pressure P (Hz),
           fO – sensors’s frequency at zero value of pressure P (Hz),
          P current value of pressure (MPa), A1 – the first degree linear coefficient,
         А1, A2, A3 - coefficients.*

Inverse:                                P(F)=BO +B1 x (F-F0) +B2 x (F-F0)2+ B3 x (F-F0)3

where: P(F) – pressure value corresponding to the current frequency of the sensor F(MPa),

         F0, B0, B1, B2, B3 – coefficients.*

Overalls

Operating Temperature, TOPR (typ/max)

-60…+80 / -196…+180**

°C

Temperature accuracy in the working temperature interval at P=0.1 MPa, no more

± 20

Hz

Resolution

0.005 (0.1)

Hz(ppm)

Aging first year/10 years max

± 15 / ± 40

ppm

Vibration Resistance (vibration from 10 to 2000 Hz with acceleration 5g during 8 houers), DF/F0

±5 max.

ppm

* the coefficients of the function are determined by individual graduation, with connecting RKMA-P-1 (21, 3, 4) to the oscillator.

** when ordering, you must specify the desired operating temperature range.

Temperature sensing quartz crystal RKT206 may be used for compensation of a temperature deviation of RKMA-P.

Precision electronic transducers, pressure gauges and pressure controllers (with the ability to compensate for temperature error)  with an accuracy class up to 0.01 are developed and manufactured based on RKMA-R.

Inverse temperature-compensated conversion function: Р(Fp, T) = C0 + C1 × (T - T0) + C2 × (T - T0)2 + C3 × (Fp - Fp0) + C4 × (Fp - Fp0)2 + C5 × (Fp - Fp0) × (T - T0)

where  Fp is the current value of the frequency of the crystal PKMA-P-OS-21 (Hz);

       T is the current temperature value (°C);

       T0, Fp0, C0, C1, C2, C3, C4, C5 are the coefficients of the transformation function determined as a result of calibration.

External dimensions

 

There are 4 main versions of the quartz manometric absolute pressure sensors RKMA-R:

  • RKMA-R-1 without rigid fixation, placed in a container;
  • RKMA-R-21 light-sized version;
  • RKMA-R-3 has a thermomechanical decoupling of the cover, which is glued to the surface of the sensor housing;
  • RKMA-R-4 has a metal fitting through which the measured pressure is supplied.

UNITS: millimeters

RKMA-P-1

RKMA-P-3

RKMA-P-4

RKMA-P-21

 RKMA R 1poz  RKMA R 3poz  RKMA R 4poz  RKMA R 21poz

1- Cover; 2- Gasket; 3- Membrane; 4- Contact pads.

 

 

Working pressure intervals

 

The upper limit of the interval of working absolute pressure P

Unit

Sensitivity (linear coefficient) A1 ± 5...20% FS)

Units

Overall dimensions, no more

Units

RКМА-0.1-1 (3;4)

0.1

MPa

22000

Hz/MPa

26 х 24 х 4.0 (6.0)

 

 

 

 

 

 

 

 

 

mm

RКМА-0.25-1 (3;4)

0.25

10000

26 х 24 х 4.2 (6.2)

RКМА-0.4-1 (3;4)

0.4

7800

26 х 24 х 4.3 (6.3)

RКМА-0.6-1 (3;4)

0.6

2800

26 х 24 х 4.6 (6.6)

RКМА-1.0-1 (3;4)

1.0

2100

26 х 24 x4.1 (6.1)

RКМА-1.6-1 (3)

1.6

1100

26 х 24 х 4.4 (6.4)

RКМА-2.5-1 (3)

2.5

1000

26 х 24 x4.6 (6.6)

RКМА-4.0-1 (3)

4.0

500

26 х 24 x4.8 (6.75)

RКМА-6.0-1 (3)

6.0

300

26 х 24 х 6.1 (8.1)

RКМА-10.0-1 (3)

10.0

160

26 х 24 х 5.3 (7.3)

RКМА-16.0-1 (3)

16.0

130

26 х 24 х 5.7 (7.7)

RКМА-0.1-21

0.1

20800

ø15 х 1.25

RКМА-0.16-21

0.2

20800

ø15 х 1.8

RКМА-0.25-21

0.25

15000

ø15 х 1.85

RКМА-0.4-21

0.4

6000

ø15 х 1.95

RКМА-0.6-21

0.6

3800

ø15 х 2.25

RКМА-1.0-21

1.6

200

ø15 х 2.35