Description

Kofloc EX700 Mass Flowmeter

Kofloc EX700 Mass Flowmeter In comparison with conventional mechanical products, the mass flow measurement/control technology used in a mass flow meter and controller extracts electrical signals from the flow without significantly influencing the temperature or pressure, thus permitting sophisticated flow measurement and control.

Technology of Kofloc EX700 Mass Flowmeter

The technology is widely used for manufacturing semiconductors, liquid crystal, optical fibers and other electronic devices, gas supply for fuel cells, and fuel gas control for burners, foods, and biotechnology, as well as for experimental facilities and production/inspection systems in many other industries.

Technical Overview & Operation

The Kofloc EX700 Mass Flowmeter utilizes a thermal mass sensing capillary bypass system. A fraction of the gas stream passes through a fine capillary tube equipped with two outer heating and temperature-sensing elements.

As gas flows through the capillary tube, heat transfers from the upstream sensor element to the downstream element in proportion to the mass flow rate ( $\dot{m}$ ) and specific heat capacity (C $C_p$ ) of the gas. The internal bridge circuit converts this thermal differential into a linear electrical signal directly proportional to standard gas flow volume ( $SCCM$ or $SLM$ ) without requiring separate temperature or pressure compensation devices

Specifications

Parameter	Specification
Manufacturer / Brand	Kofloc (Kojima Instruments Inc.)
Model Series	EX700 Series / EX700
Focus Keyword Target	Kofloc EX700 Mass Flowmeter
Measurement Principle	Thermal Mass Flow Sensing (Capillary Bypass Principle)
Target Media	Clean, Dry, Non-Corrosive Industrial Gases ( $N_2$ , $Air$ , $Ar$ , $O_2$ , $CO_2$ , $H_2$ , $He$ )
Flow Ranges	Available from $0text{–}10text{ SCCM}$ up to $0text{–}20text{ SLM}$ (Full scale variants)
Measurement Accuracy	$pm 1.0%text{ to }pm 1.5%$ of Full Scale
Repeatability	$le pm 0.2%$ of Full Scale
Response Time	$le 1text{ to }2text{ seconds}$ ( $T_{98}$ )
Signal Output	Linear $0text{–}5text{ V DC}$ (Optional $4text{–}20text{ mA}$ available via converter)
Maximum Operating Pressure	$0.3text{ MPa}text{ to }0.5text{ MPa}$ ( $3text{ to }5text{ bar}$ )
Operating Temperature	$5^circtext{C to }50^circtext{C}$ ( $41^circtext{F to }122^circtext{F}$ )

Features

Direct Mass Flow Measurement: Measures actual mass flow rates without requiring external pressure transmitters or temperature sensors.
Pressure & Temperature Immunity: Output signal remains accurate despite variations in upstream supply pressure and ambient ambient temperature.
Compact & Durable Construction: Metal-body sensor housing ensures leak-tight integrity and long-term operating stability.
Fast Response Time: High-speed thermal sensor electronics provide rapid step-response tracking for fast gas dosing cycles.

Applications

Analytical Gas Chromatography & Combustion: Precise carrier gas feed control for laboratory analysis and burner test beds.
Semiconductor & Photovoltaic Fabrication: Accurate mass flow monitoring of purge gases in thin-film deposition and etching chambers.
Bioreactors & Fermentation Tanks: Precise oxygen ( $O_2$ ) and carbon dioxide ( $CO_2$ ) sparging control in pharmaceutical bio-processes.
Industrial Heat Treatment Furnaces: Shielding gas flow control ( $Ar/N_2$ in controlled-atmosphere annealing furnaces.

Kofloc EX700 Mass Flowmeter

Technology of Kofloc EX700 Mass Flowmeter

Technical Overview & Operation

As gas flows through the capillary tube, heat transfers from the upstream sensor element to the downstream element in proportion to the mass flow rate (

\dot{m}

) and specific heat capacity (C

C_p

) of the gas. The internal bridge circuit converts this thermal differential into a linear electrical signal directly proportional to standard gas flow volume (

SCCM

SLM

) without requiring separate temperature or pressure compensation devices

Parameter

Specification

Manufacturer / Brand

Kofloc (Kojima Instruments Inc.)

Model Series

EX700 Series / EX700

Focus Keyword Target

Kofloc EX700 Mass Flowmeter

Measurement Principle

Thermal Mass Flow Sensing (Capillary Bypass Principle)

Target Media

Clean, Dry, Non-Corrosive Industrial Gases (

N_2

Air

Ar

O_2

CO_2

H_2

He

)

Flow Ranges

Available from

0text{–}10text{ SCCM}

up to

0text{–}20text{ SLM}

(Full scale variants)

Measurement Accuracy

pm 1.0%text{ to }pm 1.5%

of Full Scale

Repeatability

le pm 0.2%

of Full Scale

Response Time

le 1text{ to }2text{ seconds}

(

T_{98}

)

Signal Output

Linear

0text{–}5text{ V DC}

(Optional

4text{–}20text{ mA}

available via converter)

Maximum Operating Pressure

0.3text{ MPa}text{ to }0.5text{ MPa}

(

3text{ to }5text{ bar}

)

Operating Temperature

5^circtext{C to }50^circtext{C}

(

41^circtext{F to }122^circtext{F}

)

Features

Direct Mass Flow Measurement: Measures actual mass flow rates without requiring external pressure transmitters or temperature sensors.

Pressure & Temperature Immunity: Output signal remains accurate despite variations in upstream supply pressure and ambient ambient temperature.

Compact & Durable Construction: Metal-body sensor housing ensures leak-tight integrity and long-term operating stability.

Fast Response Time: High-speed thermal sensor electronics provide rapid step-response tracking for fast gas dosing cycles.

Applications

Analytical Gas Chromatography & Combustion: Precise carrier gas feed control for laboratory analysis and burner test beds.

Semiconductor & Photovoltaic Fabrication: Accurate mass flow monitoring of purge gases in thin-film deposition and etching chambers.

Bioreactors & Fermentation Tanks: Precise oxygen ( $O_2$ ) and carbon dioxide ( $CO_2$ ) sparging control in pharmaceutical bio-processes.

Industrial Heat Treatment Furnaces: Shielding gas flow control ( $Ar/N_2$ in controlled-atmosphere annealing furnaces.

Kofloc EX700 Mass Flowmeter

Product Note:

Description