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for easy cleaning
Sensor can be replaced in fifteen seconds -- typically a 2-1/2 year electrode life.
316 SS housing -- titanium optional
Cable can be replaced within fifteen seconds with pHionics' patented connector system. 0.050 thick Polyurethane jacketed, water-blocked, shielded, Kevlar reinforced -- better than 'marine grade'. FEP jacketed cable optional -- for those tougher applications.
Isolated dissolved oxygen and temperature outputs -- no ground-loops!
Dissolved Oxygen Transmitter
For over 30 years pHionics has manufactured isolated water quality transmitters for monitoring and control
submersible water quality transmitters
A typical application shown with anti-blowout, 316 SS fitting
Simply lower the transmitter and cable into the tank, lake, well, etc.. For applications that require more stability and/or protection of the cable and transmitter from mixers, chemical injection points, etc. -- reverse the cmp34s compression fitting and mount at the end of a standpipe or equivalent, as shown.
Features and Benefits
The STs series of submersible water quality transmitters have an integrated preamp and an isolated 'true 2-wire', 4-20 ma transmitter. Two independent channels simultaneously transmit a dissolved oxygen (DO) and temperature signal -- two wires for DO and two wires for temperature. The compact design afforded by the patented pHiConn (TM) keyless connection system -- and the 316SS (titanium optional) and Delrin construction -- make the rugged sensor/transmitter ideal for applications such as process control, data acquisition, wastewater treatment, and, groundwater monitoring, The units can be submersed to 200 feet (approximately 100 psi). Individual units can be combined to make redundant or multiparameter modules using the pHionics' patented pHiKLIP (TM) array system. The pHiKLIP (TM) system also allows for the units to be used in in-line (insertion) applications without fear of blow-out. As with all pHionics' designs, the sensor/transmitters are designed with 'ease of service' as a primary goal.
The 'true 2-wire', 4-20 ma STs series sensor/transmitters send a current proportional to the parameter being measured on the same two wires that provide the power (7 to 40 volts dc). Current transmission allows for long runs of inexpensive cable or wire (up to three miles) that is virtually noise-free without any signal loss that is common to voltage (IR drop) or digital (capacitance affecting 'rise/fall' timing). The seven volt operation allows the units to be powered by 12 volt battery systems with 5 volts of compliance, making them compatible with RTU's and solar powered applications. The units are intended for calibration via software supplied with the datalogger, PLC, or through the DCS.
The dissolved oxygen signal on Channel 1 is automatically temperature compensated -- correcting for membrane and solution temperature changes. This is not to be confused with the temperature channel of the transmitter, which provides an independent, isolated, 4-20 ma output proportional to the 0 to 50 Celsius range on Channel 2. The auto-polarity correction feature directs the applied supply voltage to allow for proper operation regardless of wire hookup. The Red and Black wires are for Channel 1 -- dissolved oxygen, and the White and Green wires are for Channel 2 -- temperature.
n Isolated outputs
on all pHionics transmitters
n No ground-loops -- will operate in tough process applications
n 0-50 Celsius
temperature channel on all transmitters
n A temperature transmitter at no additional cost
n 'True 2-wire' 4-20 ma
n No third wire required -- which can result in damage due to improper wiring
n Reversible input protection and
n Transmitter cannot be wired incorrectly – will work even if wires are reversed – preventing damage to transmitter
n Small, 3/4" (19mm) diameter
n Ideal for submersion in wells, and lower mounting costs, at higher pressures
temperature compensation of dissolved oxygen
n Corrects for temperature changes
n Sensor (electrode) life
of thirty months in typical applications
n Resulting in a low cost of ownership (approx $10/mo)
n Insertion (in-line)
or submersion capability
n Insertion (in-line) or submersion capability
n Patented, field replaceable sensors and
n The entire transmitter does not have to be scrapped, if only one or two components are damaged
n KevlarTM (DuPont) reinforced, shielded, water-blocked, polyurethane jacketed cable -- standard
n Added pull strength, low noise, and
limited water damage due to compromised cable or transmitter -- not simply 'marine grade'
n Optional titanium housing and
FEP jacketed cables
n For the extremely difficult applications
n Double o-ring seals
n Provide exceptional sealing
for reliability on cable and sensor seals
n No potting -- Fully engineered transmitter with rebuildable components -- no potting required
to conceal poor design
n No premature failures due to poor sealing and curing of potting compounds – plus allows for the capability
of easily replacing the cable, housing, or electronics – or simply exchanging the cable for a different length. Reduced weight.
The large surface area of the sealed, galvanic measuring cartridge allows for accurate operation of the transmitter within minutes of installation. This is unlike the delays common to typical sensors that can sometimes take 24 hours to stabilize after installation or membrane/solution replacement. The sealed cartridge concept also reduces the man-power that is required with other sensors that often need to be refilled and have the membrane replaced every six months -- and the inherent problems associated with the process. The 30 month typical cartridge life results in a nominal cost of ownership of $10/per month, and can be replaced within 15 seconds -- further lowering costs, and simplifying use.