ASTI - Model AST-DO-UNIVERSAL -Galvanic Dissolved Oxygen Sensors

• Disassembled galvanic DO measuring cell ready for rebuilding
• Cathode & anode on front tip of sensor are shown to the bottom right
• High stability thick membrane installed into cap is shown immediately above
• Membrane & electrolyte solution are easily replaced by anyone in just minutes when required
• Virtually unlimited sensor lifetime with rebuildable DO cell ensuring very low cost of ownership.

AST-DO-UNIVERSAL-CONVERTIBLE dissolved oxygen galvanic DO sensor shown in convertible without preamplifier with shielded black composite cable (max 15 meters, 50 feet cable). In the with integral analog preamplifier configuration (not shown) up to 100 meters (330 feet) total cable length can be supported. Other options available but not shown are waterproofing options for fully submersible installations without the use of an immersion tube. In addition the Q7M waterproof NEMA 6P rated quick disconnect snap connector is available for DO sensor in the with integral preamplifier configurations (see further below). AST-DO-UNIVERSAL dissolved oxygen sensors are also available in twist lock quick disconnect bayonet style for inline installations for easy removal & insertion from process for cleaning. Sanitary tri-clamp & HOT-TAP valve retractable installations supported using same 316SS sensor holder installation hardware as for the pH/ORP/ISE sensors.

• Thick-wall TEFLON™ (PTFE) membrane ensures very high stability, low-drift and high durability in aggressive industrial applications & minimizes frequency of membrane replacement
• No special maintenance needed. Just wipe the membrane periodically as required.
• Galvanic dissolved oxygen cell with true zero means only a slope (span) calibration performed clean and dry in air is required. No wet solution calibration is ever needed and so no calibration solutions are ever required for calibration.
• No look-up tables are needed since the 3TX-DO transmitter computes the dissolved oxygen ppm value associated with the 100 percent saturation dry in air condition used for calibration at the current measured temperature (from integral Pt element) and the user entered atmospheric pressure. The automatic calibration mode autoreads the mV potential and then assigns the proper slope (span) mV per ppm response for the sensor. Manual calibration mode is also available if the fully automatic calibration mode is not desired.
• Membrane and electrolyte solution are simple to replace allowing for extremely low ongoing cost of ownership and a theoretically unlimited service lifetime
• The AST-DO-UNIVERSAL DO sensor is not sensitive to hydrogen sulfide gas
• Temperature compensation is built-in & performed automatically inside sensor for reliable readings
• Extremely high stability such that calibration is seldom required with thick rugged TEFLON™ (PTFE) membranes that are easily cleaned. The required frequency of cleaning is low for most applications. If the membrane is damaged, it can be replaced by anyone at very negligible cost in just a few minutes from start to finish.
• Since the galvanic AST-DO-UNIVERSAL dissolved oxygen sensors generate their own mV potential, they do not suffer from cable sensitivity issues that many polarographic (amperometric) DO sensors can that are powered by the transmitter resulting in issues such as warm-up time, drift and related problems.
• AST-DO-UNIVERSAL dissolved oxygen sensors have very little sensitivity to environmental issues such as wind or electrostatics (in dry climates) as well as readily supporting long cable runs or deep submersion installations. The AST-DO-UNIVERSAL in the with integral preamplifier configuration cabling can be bridged across ordinary terminal blocks housed inside a simple waterproof J-box assembly if the cable length needs to be extended.
• Correct measurements with flow as low as 1 cm/s making it suitable for most any common installation type.
• Built-in integrated temperature compensation inside sensor means that temperature sensor is only required if percent (%) saturation is to be computed and for accurate sensor calibration dry in air
• Typical clean water use keeps calibration up to 1 year at a time with membrane lasting 3 to 5 years. More dirty and aggressive applications will need to have membrane replaced more frequently as may be required but calibration need be done very infrequently.
• Spare membranes and internal electrolyte filling solution are available after the ample initial supplies are used at a nominal cost. Standard sensor package contains all parts to operate for a two to five year period for most applications.
• Custom configurations and options available upon request (minimum order quantity may apply).

Core Features of Rugged AST-DO-UNIVERSAL Industrial Dissolved Oxygen Sensors in Convertible Configuration for Tough Inline, Immersion & Submersible Installations

• Inline Insertion depth from 1.5 inches (standard) to 3.5 inches (special order option)
• Ready for inline or immersion use standard, submersible with waterproofing option
• Waterproofing seal option is available for complete cable isolation for fully submersible
  installations & applications employing field washdowns and/or moist & humid conditions
• Pt1000 temperature element used to compute the % saturation at the current temp
• Without preamplifier configuration has 3 meters (10 feet) of cable standard, Maximum
  cable length in this configuration is 15 meters (50 feet) cable submersible to 25 feet
• With integral conventional preamplifier configuration also has 3 meters (10 feet) of
  cable standard, Maximum 100 meters (330 feet) cable submersible up to 50 feet
• Thick rugged PVC jacket on sensor cable suitable for aggressive field use

• Measurement Range: 0-600 percent (%) saturation, 0-60 ppm range (Lowest Limit 0.1ppm) *
• Operating Temperature: -5 to +50 °C (+23 to +122 °F)
• Convertible 3/4"-3/4" MNPT Configuration Installation Styles: Inline, Immersion or
• Submersible with immersion tube or waterproofing option installed
• Twist Lock Configuration Installation Styles: Inline with 1"MNPT Twist Lock Receptacle
• Immersion or Submersible with immersion tube or waterproofing option installed on rear 1"MNPT threads
• Sanitary/HOT-TAP Configuration Installation Styles: Inline with mating 316SS sanitary tri-clover sensor holder,
• Valve retractable when used with with mating 316SS HOT-TAP hardware assembly,
• Immersion or Submersible (with immersion tube or waterproofing option installed)
• Temperature Element: Standard with Pt1000 temperature sensor
• DO Measuring Cell Material of Construction: DELRIN® (Polyoxymethylene, POM)
• Sensor Body Material of Construction: RYTON® R-4-230BL (Poly-Phenylene-Sulfone, PPS)
• Dimensions: See drawing above and specification sheet(s) for details
• Cable Length Without Preamplifier: Standard 10 feet (3 meters), Max is 50 feet (15 meters)
• Cable Length With Integral Preamplifier: Standard 10 feet (3 meters), Max is 330 feet (100 meters)
• Measurement Principle: Galvanic cell, self polarizing (a.k.a. active type) & internally self temperature compensating
• Signal Response Wetted in Solution: Slope (span) is 1mV to 5mV per DO ppm depending on exact conditions
• Signal Response Dry in Air: Typically 10mV to 40mV depending on exact conditions
• Signal Response Time: Typically 10 to 20 seconds near ambient (response time is temperature dependent)
• Signal Response Resolution: 1% saturation absolute
• Signal Response Repeability: Typically ±1% of actual measurement under the exact same conditions
• Calibration: Slope (span) determined from automatic dry in air calibration. No zero calibration required for true galvanic DO cell.
• Initial Impedance Without Preamplifier: < 2 MegaOhms @ 25°C
• Initial Impedance With Preamplifier: < 2 KiloOhms @ 25°C
• Flow Requirements, Water: Minimum flow dependent on DO and temperature, typically 1 cm/sec, suitable for most uses
• Supplied With: 10 each spare thick high stability membranes with O-rings, 125 ml electrolyte filling solution,
• Tool for installation and removal of membranes from ring inside cap