Capacitive level switch（QH Type, QS Type, SH Type）

Explosion-proof High Pressure Gas Safety Association inspection product

～A wide range of variations from mass-produced economic products to specially designed products～

Installation image

Model	QH Type　High-frequency absorption automatic correction / series resonance type (adhesion resistant type) QS Type　Ultra-sensitive, parallel resonance type (static electricity resistant type)
Explosion-proof specifications	SH Type　Intrinsically safe explosion-proof structure ExiaII CT5 (TIIS) Explosion-proof structure (ATEX)

Main application

Liquid level, powder level
interface
Separatory funnel
Foam surface
Liquid level detection ignoring bubbles
Admittance type (AD Type) for highly conductive adhesion
Carbon slurry, Seabed sediment (containing minerals)
Sludge, Seawater (mineral adhesion)
Metal powder slurry, semiconductor

Features

QH, SH Type

Both conductive and insulating objects can be detected
“Automatic correction function” to avoid malfunction due to adhesion or accumulation of conductive material
Sensitivity can be set simply by turning the sensitivity dial.
In addition, a wide range of measurements is possible with the detection sensitivity switch.
Uses nitrogen-filled relay
Long-life without drive
Φ60 small head case (SUS, aluminum)

QS Type

Suitable for measuring high insulation because it uses an ultra-sensitive amplifier.
“Separate type” for tanks installed in high places and narrow places can be adjusted on the panel side while looking at the meter mounted on the amplifier side.
Easy centralized management on the control panel side
Complete measures against fluctuations in power supply voltage
Strong against vibration
Sensitivity can be set according to the object to be measured by simply turning the SET volume

Specifications

Sanitary specifications：

#400 buff finish equivalent
Electropolishing
Passivation treatment
Condensation resistant treatment
IDF sanitary ferrule / Seat / Nut mounting

Operating principle：

It consists of an oscillator circuit and a detector
Since the capacitance of the object to be measured and the capacitance of air is significantly different, the capacitance change due to contact with liquid contact, and powder is converted into an electric signal to operate the relay.

Other features：

Insulating Ideal for detecting highly viscous liquids and insulating resin powders
A high degree of freedom in designing the detector.
According to the site conditions, it is possible to manufacture detection parts such as small size, high strength, flat, and pipeline.
Take the high pressure gas equipment test for the product alone^{* Note 1}
Explosion-proof structure with integrated amplifier (ATEX).
The effects of static electricity are almost negligible^{* Note 2}
An operation indicator LED is attached to the sensor board, making it easy to check the operation on-site.
Since it is manufactured at our factory, it has a short delivery time.

Wet contact material：

SUS304, SUS316, SUS316L, PVC, Heat-resistant PVC, Teflon, FRP, FEP, PFA, Titanium, Hastelloy B, Hastelloy C276, Nickel, Tantalum, Ceramic, Glass lining, SS400

Operating temperature：

Up to 500℃ (Possible by individual design)

Withstand pressure：

Up to 25MPa (Possible by individual design)

Input power supply：

QH Type QS Type	Integrated or Separate type	AC105V/210V（±10％）　50/60Hz
QH Type QS Type	Integrated or Separate type	DC24V
SH Type	Separate type	AC100V（±10％）　50/60Hz

output：

Relay contacts (AC250V / DC30V,5A),Transistor

Standard mounting dimensions：

Flange　JIS5K/25A,　1 ”PT screw　IDF ferrule（1.5S, 2S

*Note 1：
We can also prepare only the necessary documents (strength calculation, test report, mill sheet) for the KHK examination

*Note 2：
When the tank contents are charged with static electricity, the static electricity flows from the level switch’s detection electrode to the ground electrode and from the mounting flange or mounting screw to the tank ground. If the ground line is wired, it can also be routed to the ground wire. This technique is instrumental in preventing electrostatic explosions.

Description of sensitivity

Model	Amplifier sensitivity	Maximum detection capability	Object to be measured
QS	X： High sensitivity	0.1pF	Insulating powder, Conductive liquid
QH / SH	X： High sensitivity	0.5pF	Insulating powder, High viscosity conductive liquid
QS / QH / SH	B：Wide area sensitivity	3pF～2Ω	Conductive liquid

Example of measurement

Electrical characteristics	Low　←		Conductivity		→　High
Electrical characteristics	∞Ω　←		Resistance value		→　2Ω
liquid	Crude oil / Heavy oil Petroleum oil Toluene Methanol Acetone Transformer oil Varnish Resin concentrated solution Solvent Paint Silicon oil Grease Asphalt Oil and butter Chocolate Liquid sugar Pure water	Urethane Alcohol Beer Whipped cream	Ammonia Human waste Water-based paint Soy milk Makeup cream Water	Aqueous wax Slurry Milk Pulp	Alkaline caustic soda Hydrochloric acid / Sulfuric acid Surfactant Shampoo Rinse Lime milk Slaked lime solution Electrolyte	Miso Minced fish meat Sauce Sludge Dehydrated cake Livestock drainage
Powder / Granular material	Resin pelletsPolyester pellets Nylon chips Rice / Wheat / sesame Sugar Corn Starch Lime / ash / sand Iron oxide powder Soap powder					Carbon Metal powder
	Compatible model
	High　←		Sensitivity		→　Low
QH Type SH Type（Explosion-proof）	←		Measurable			→
QS Type	←	Measurable	→