Technology History

Development of a capacitive level switch and capacitive level transmitter derived from the practical application of capacitance using semiconductor material

In 1965, vacuum tubes were mainly used for both level controllers (level switches) and level transmitters. However, they posed problems such as high electricity consumption and high temperature (not suitable for explosion-proof construction), unstable measurement accuracy, and production that required skilled workers (high cost).

Toyoharu Iizaka joined Daiki Kogyo Co., Ltd. in 1966. Shortly after joining the company he succeeded in the practical application of capacitance using semiconductor material, which used to be considered extremely difficult, for the first time. He completed a capacitive level switch, capacitive level transmitter, and self-balancing interface level transmitter, and obtained patents as an inventor.

In his 20s, Iizaka was appointed engineering manager and as the person in charge of developing industrial instruments. He continued to work with Morimoto, Matsumura, and Tsutsui to complete the lineup of capacitive level switches (QH and SH types), capacitive level transmitters (QB and SB types), and self-balancing interface level transmitters (QC and QS types). They appeared to be on the path to success as salaried engineers when in September 1974, the company went bankrupt, abruptly bringing their careers to an end.

Founding of DITECH, Ltd.

Iizaka was repeatedly solicited by a major manufacturer with an attractive offer. Meanwhile, due to strong requests and tremendous support from customers, the four founding individuals held frequent discussions that continued late into the night. Eventually, in October 1974, Iizaka, Morimoto, Matsumura, and Tsutsui (the current plant manager) founded DITECH as a privately owned enterprise.
It was both morally and legally improper to be released from debt but continue to use the same trading name of the former company, so the company name was changed to DITECH (an acronym of Dielectric, Detector, Electrostatic, Technology).
Many people applied to join the new company, but it was financially difficult to hire more personnel, so DITECH was founded by the four individuals.

The product names (trademarks) of QH, SH, QB, SB, QC, and SC types were not used for the same reason mentioned above. New circuits were designed at the Amagasaki Plant (which was available for lease) to develop improved capacitive level switches (NQH and NSH types), capacitive level transmitters (QBS and NSB types), and self-balancing interface level transmitters (NQC and NSC types).

In May 1975, the company was incorporated as DITECH, Ltd. because the prospects for the business looked good.

May 1975 Capacitive Level switch (Non-explosion-proof type)
Model NQH, developed and released
May 1975 Capacitive Level switch (Explosion-proof type)
Model NSH, developed and released
May 1975 Capacitive Level transmitter (Non-explosion-proof type)
Model QBS, developed and released
May 1975 Capacitive Level transmitter (Explosion-proof type)
Model NSB, developed and released
May 1975 Impedance type Level switch (Non-explosion-proof type)
Model NQS, developed and released
May 1975 Impedance type Level switch (Explosion-proof type)
Model NSS, developed and released
May 1975 Self-balancing interface Level transmitter (Non-explosion-proof type)
Model NQC, developed and released
May 1975 Self-balancing interface Level transmitter (Explosion-proof type)
Model NSC, developed and released
Jul. 1975 Capacitive water・fluid Level transmitter
Model NQB (Present name; Model QBS-WF), developed and released
Feb. 1976 Beer sensor (Present name; Conductive switch)
Model DR, developed and released
Apr. 1976 Level switch operation checker, developed and released
May 1976 mm-class oil film detector Model NQH-OFm, developed and released
Feb. 1977 Lightning arrestor Model SK, developed and released
Mar. 1977 Densitometer for sediment, developed and released
* The compensating probe technology, which was created while developing the densitometer,
was used for level transmitters, leading to the development of a Relative permittivity-correcting Level transmitter.
Apr. 1977 Double electrodes Level switch, developed and released
Nov. 1977 Thickness detector for centrifugal separator
(Present name; Thickness measuring device for centrifugal separator), developed and released
Dec. 1977 Two detecting points Level switch
(Present name; Multi-detecting points Level switch), developed and released
Dec. 1977 Vibrating Level switch (Non-explosion-proof type)
Model DTA-A, developed and released
Apr. 1978 Vibrating Level switch (Explosion-proof type)
Model STA-A, developed and released
May 1978 Capacitive oil-in-water meter, developed and released
May 1979 Capacitive moisture-in-oil meter, developed and released
Sep. 1979 Magnet bias system Vibrating Level switch (Non-explosion-proof type)
Model DTA-M, developed and released
Nov. 1979 Capacitive Moisture meter Model QBS-MM, developed and released
Dec. 1979 Separated type indicator (Explosion-proof type)
Model LI-100, developed and released
Dec. 1979 Wave height meter, developed and released
Dec. 1979 High sensitive type Level switch (Present name; Net capacitive Level switch)
Model DLS, developed and released
Feb. 1980 Height meter (Present name; Non-contact self-balancing Level transmitter)
, developed and released
Apr. 1980 Deposited sand quantity measuring device, developed and released
Sep. 1980 Magnet bias system Vibrating Level switch (Explosion-proof type)
Model STA-M, developed and released
Nov. 1980 Photoelectric film detector, developed and released
Jul. 1981 Weir type Flowmeter Model NQBH (Present name; Model QBS-FM)
, developed and released
Aug. 1981 Vertically anchored wire Level transmitter for large tanks
, developed and released
Sep. 1981 Guard type Level transmitter (Non-explosion-proof type)
Model NQS-G, developed and released
Nov. 1981 Pipe clogging detector, developed and released
Mar. 1982 Variable air dielectric capacitor (Present name; Capacitance generator)
Model SVC-500, developed and released
Apr. 1982 Three detecting points Level switch (Present name; Multi-detecting points Level switch)
, developed and released
May 1982 Level transmitter for rotary kiln, developed and released
Aug. 1982 Foam detecting switch Model NSH-FO, developed and released
Feb. 1983 Alcohol concentration meter, developed and released
May 1983 Static arrestor Model SP, developed and released
Nov. 1983 Release agent concentration meter, developed and released
Mar. 1984 Relative permittivity-correcting Level transmitter
Model NSB-DC, developed and released
Apr. 1984 Float type Level tramsmitter, developed and released
Apr. 1984 Level switch for glass, developed and released
Apr. 1984 Pipe flow rate meter (Present name; Level transmitter for vertical piping)
, developed and released
Jul. 1984 Drain pipe leakage detector, developed and released
Jan. 1985 Conductivity meter, developed and released
Jul. 1985 Self-balancing interface Level transmitter Model NQC-V
, developed and released
Jul. 1985 Impact type falling-powder flow meter (Present name; Impact type falling-powder detector)
, developed and released
Aug. 1985 Moisture meter for conveyer belt, developed and released
Dec. 1985 Capacitive leakage detector (Present name; Drain pipe leakage detector)
, developed and released
Apr. 1986 Density measuring device for fluidized bed, developed and released
May 1986 Capacitive floc sensor, developed and released
Sep. 1986 Vibrating floc sensor, developed and released
Oct. 1986 Vibrating viscometer, developed and released
Nov. 1986 Lump detecting meter, developed and released
Jan. 1987 Relative-permittivity meter, developed and released
Jan. 1987 Impedance type Level transmitter Model IP, developed and released
Mar. 1987 Level transmitter for molten metals Model DIM, developed and released
May 1987 Vibrating flat Level switch, developed and released
Oct. 1987 Relative-permittivity meter for gas, developed and released
Nov. 1987 Microwave-based flowing-powder detector
Model MM, developed and released
Dec. 1987 Counter electrode type Level transmitter, developed and released
Feb. 1988 Relative-permittivity (ε.tanδ) measuring device
(Present name; Relative-permittivity meter for laboratory), developed and released
Apr. 1988 Lump detector Model D-S, developed and released
Aug. 1988 Density meter for pipeline, developed and released
Jul. 1989 Capacitance generator Model SVC-300, developed and released
Nov. 1989 Buildup meter and Densitometer, developed and released
Dec. 1989 Moisture meter for Granulated slag, developed and released
Aug. 1990 Capacitive Level switch Model NSH-C, developed and released
Oct. 1990 Capacitive Level switch Model NQH-Y, developed and released
Mar. 1991 Ultrahigh sensitive Level switch Model MPH, developed and released
Aug. 1991 Capacitive Level switch Model NQH-C, developed and released
Sep. 1991 Net capacitive Level switch Model OCT, developed and released
Oct. 1991 Deviation meter, developed and released
Mar. 1992 Ultrahigh sensitive Level transmitter Model MPB, developed and released
May 1992 Puluse-feeding catalyst passage meter, developed and released
Jun. 1992 Operator’s hand presence detector (Present name; Three-dimensional presence detector)
, developed and released
Jun. 1992 Capacitive Level switch Model NSH-Y, developed and released
May 1994 Moisture meter for large flexible containers
(Present name; Moisture detector for large flexible containers), developed and released
May 1994 Portable moisture detector, developed and released
Mar. 1995 Guard type Level transmitter, developed and released
Jun. 1995 μm-class ultrathin oil film detector, developed and released
Oct. 1996 Vibrating flat Level switch (High temperature type), developed and released
Aug. 1997 Catch prevention detector (Present name; Three-dimensional presence detector)
, developed and released
Apr. 1998 Moisture densitometer for incineration ash, developed and released
Sep. 1998 Vibrating Level switch (High temperature type), developed and released
Nov. 1998 Level transmitter operation checker, developed and released
Mar. 1999 Metal powder detector (Present name; Electromagnetic induction type metal detector)
, developed and released
Jul. 1999 V-type tabletop vibrating viscometer (Present name; Vibrating viscometer for laboratory)
, developed and released
Feb. 2003 Leakage detector (Present name; Minimal-leakage meter for piping)
, developed and released
Dec. 2005 Pipeline type Level transmitter, developed and released
Jul. 2006 Vibrating viscometer for low and high viscosity, developed and released
Aug. 2009 Electrostatic voltmeter for laboratory, developed and released
Dec. 2009 Level switch for molten metals, developed and released
Jun. 2010 Vibrating viscometer (Explosion-proof type) Model NSB-V, developed and released
* Conventional viscometers were the separated explosion-proof type (with a converter separated from the power source).
The design was overhauled and an integrated explosion-proof type viscometer was developed.
Jul. 2010 Electrostatic ammeter Model S-22, developed and released
Aug. 2012 Turbine Flow meter Model DM-11, developed and released
Sep. 2012 Force-feeding catalyst passage meter, developed and released
Jul. 2014 Moisture detector for large flexible containers (Built-in type)
, developed and released
Aug. 2014 Capacitive Level switch Model NQH-C (Improved type), developed and released
Oct. 2014 Vibrating viscometer (High temperature sensor), developed and released
* The permissible temperature range of conventional detectors was between −50°C and +350°C.
DITECH developed a high-temperature sensor for an expanded temperature range between −200°C and +600°C.
Dec. 2014 Blower-equipped Level switch Model DTA-BL, developed and released
Aug. 2015 Lump detector (Explosion-proof type) Model LD-11, developed and released
Jan. 2016 Blower-equipped Level transmitter, developed and released
Oct. 2017 Moisture detector for large flexible containers (Straight rod type)
Model D-MFR, developed and released
Jul. 2018 Turbine Flow meter (Explosion-proof type) Model TM-11, developed and released