How to choose the Best Product

Vacuum gauge

Vacuum Gauge Selection Guide

Vacuum and pressure measurement are essential basic technologies for various industries such as manufacturing processes, production technology, research and development, and quality control.

Through continuous research and development, KVC manufactures highly reliable vacuum gauges that meet the needs of customers in various fields.

We have a product line suitable for a variety of applications that can measure everything from atmospheric pressure to ultra-high vacuum.

In addition, a variety of products are available depending on the intended use, ranging from an integrated vacuum gauge with a compact display to a separate gauge that can be mounted on a panel.

                                                                                                                       Unit (Torr) 

Pirani Vacuum Gauge Model

This is a gauge that uses the fact that the thermal conductivity of a gas is proportional to the degree of vacuum under voltage.

Connect one end of the tube with the filament to a vacuum device and pass a constant current through the filament.

This is a gauge that measures the electrical resistance of the filament to know its temperature, that is, the heat lost from the filament, and indirectly measures the degree of vacuum in the vacuum device from that measurement value.

MANOMETER Gauge Model

Also called a piezoelectric pressure sensor, it is a gauge that detects the voltage generated by stress by applying the displacement or strain generated in the elastic body due to pressure to the piezoelectric element.

Because the output impedance is very high, measurements require an impedance conversion circuit.

Although the sensitivity is very high, because it uses dielectric polarization, the induced voltage is proportional to the time derivative of the applied stress, and the voltage decreases with time due to leakage, so it cannot measure static pressure.

This gauge has the advantages of small size, high sensitivity, high-speed response, and heat resistance.

CONVECTION Gauge Model

Convection gauges are very similar to Pirani gauges in that an electric current is supplied to the filament to maintain a constant temperature.

As molecules interact with the filament, heat is removed from the filament and more current is needed to maintain a constant temperature.

This current differential is converted to voltage and then to pressure. This gauge design allows for uniform movement around the filament due to convection. 

This provides more accurate readings by minimizing pockets of molecules sticking to specific parts of the filament.

COLD CATHODE Gauge Model

A cold cathode gauge is a vacuum gauge composed of a part that ionizes gas molecules, an electrode to easily collect the generated positive ions, and a part that indicates the size of the generated ion current.

The filament has no contamination and oxidation problems, produces much less gas, and has a simple structure, making it easy to handle.

Using panning discharge, a discharge occurs inside the anode to generate ions and measure the ion current.

HOT CATHODE Gauge Model

An ion gauge consists of a filament, a grid, and an ion collector.

The filament supplies ionized electrons, the grid attracts these electrons, and the ion collector attracts ions, which neutralize them and release electrons.

The number of gas molecules that become positive ions by ionizing the gas is measured using ion current, and the degree of vacuum is measured using the fact that ion current is proportional to the density of gas molecules.

In case of Log Scale, Log(Pvac) = analog output(Vdc)

ex) If the vacuum level is atmospheric pressure (760 Torr), Pvac = 760 Torr, so Log(760) = approximately 2.881Vdc (However, the bias value is different for each product.)

The Set Point function is a function that allows vacuum pump ON/OFF or valve ON/OFF control through alarm relay contacts.

The detailed operation of the function is as follows.

1. Alarm action when vacuum is higher than set (upper limit) pressure

2. Alarm action when vacuum is lower (lower) than set

If you call the representative number (☎82-32-234-3030) or contact the representative email (kvcins@kvcins.com ), we will answer in detail.

Because the sensor is affected by its surroundings, the filaments inside the sensor are often disconnected and the sensor cannot be used.

The sensor is welded, so only the internal filaments cannot be replaced separately, and the sensor must be replaced.

If the Err mark appears, it is a sensor open circuit. 

If it is disconnected, you can check it directly by referring to the image below.

If the sensor is open, the sensor must be replaced, and if it is not open, please contact the representative number (☎ 82-32-234-3030).

                             Convection Sensor                                                         Pirani Sensor

Sensor recalibration is possible, but once the characteristics have changed, the value may change again in a short period of time even after the recalibration.

However, if the inside of the sensor is contaminated, re-calibration is not possible.

Available. 

However, in the case of Pirani Gauge and Connection Gauge, which contain filaments, the actual vacuum degree and value may be displayed differently depending on the type of gas used in the process because our product is calibrated using nitrogen.

The sensor is a consumable, and the degree of contamination of the sensor varies depending on the process, 

such as whether gas is used or whether dust is generated, and the cycle of the sensor being contaminated and disconnected is different, 

so no replacement cycle is set.

The sensor is a consumable and cannot be cleaned. 

However, the Penning Gauge (Cold Cathode Gauge) can be cleaned inside.

The Dead Band function is a function that determines when the alarm is turned off at the set point, and you can specify the Dead Band according to the percentage.

(0-99%) Individual Dead Band settings are possible for each Set Point.

The controller is not affected by the installation location.

However, in the case of SHIM Sensor, the installation direction must be parallel to the ground.