Vaisala K‑PATENTS® Teflon Body Refractometer


Vaisala K‑PATENTS Teflon Body Refractometer PR-23-M


for chemically aggressive solutions and ultra-pure fine chemical processes

The PR-23-M has a built-in flow cell designed to keep all metal and other easily corroding parts from coming into contact with the process liquid. All the wetted parts are made of non-metallic materials, either PTFE (Teflon®) or PVDF (Kynar®), and thus the PR-23-M sensor withstands corrosion well.

The PR-23-M sensor is connected to the process by a G1/2 inch female or a 1/2 inch NPT process connection.

The measurement range covers 0-100 % by weight. The accuracy is typically ±0.1 % b.w. and the measurement is automatically temperature compensated. Low and high concentration alarms can be configured. Because of the digital sensing technology, even large amounts of suspended solids, bubbles or color changes do not affect the measurement or the accuracy.

Each sensor is provided with a calibration certificate comparing a set of standard liquids to the actual sensor output. The calibration and accuracy can be verified onsite with the certified Refractive Index liquids and K-Patents documented procedure.

  • Universal calibration of each sensor: All sensors are freely interchangeable.
  • Full measurement range Refractive Index nD 1.3200 – 1.5300, which corresponds to 0-100 % by weight.
  • Dual connectivity: one transmitter can operate two sensors. A second sensor can be easily integrated later.
  • Completely digital system: particles and bubbles do not affect operation or accuracy.
  • CORE-optics: no drift, no re-calibration, no mechanical adjustments.
  • Ethernet connection and remote panel for data-logging and remote operation.
  • Process temperature range: -20°C – 130°C (-4°F – 266°F)
  • Fast process temperature measurement by built-in Pt1000 and automatic temperature compensation.
  • Easy on-site instrument verification within users’ own quality assurance system with standard Refractive Index liquids.
  • ATEX approved for Zone II, area classification EX II 3 G EEx nA II T4.
  • ATEX approved for Zones 0 and 1, area classification ATEX II 1G Ex ia IIC T4 (only Intrinsically safe PR-23-M-IA with single sensor transmitter STR).
  • FM approved for Class I, Div. 2, Groups A, B, C and D, T6.
  • CSA certified for Class I, Div. 2, Groups A, B, C and D, T4.
  • cCSAus certified for Electrical Safety, Sensor: Class I, Pollution Deg. 3; Transmitter: Class I, Pollution Deg. 2; Installation Cat. II.
The Saunders Body PR-23-W and Teflon Body PR-23-M Refractometers provide accurate means for measuring liquid concentrations in chemically aggressive solutions that corrode, foul or otherwise destroy metal parts as well as in ultra-pure fine chemical processes, where metal parts cannot be used.
    Acetic acid CH3COOH, Ammonium fluoride NH4F, Ammonium hydroxide NH4OH, Ammonium sulphate (NH4)2SO4
    Calcium hypochlorite Ca(ClO)2, Copper chloride CuCl2, Citric acid C6H8O7, Chromic acid CrO3
    Ferric chloride FeCl2, Fluosilic acid, Formic acid HCO2H
    Hydrochloric acid HCl, Hydrofluoric acid HF, Hydrogen peroxide H2O2, Buffered HF (BHF), Aqua Regia HNO3/HCl
    Lactic acid C2H4(OH)COOH
    Magnesium chloride MgCl2, Nickel chloride NiCl2, Nitric acid HNO3
    Phosphoric acid H3PO4, Potassium carbonate K2CO3 · 11/2 H2O, Potassium hydroxide KOH, Potassium thiocyanate KSCN, Potassium nitrate KNO3
    Sodium bicarbonate NaHCO3, Sodium carbonate Na2CO3, Sodium chloride NaCl, Sodium dichromate Na2Cr2O7 · 2H2O, Sodium hydroxide NaOH, Sodium hypochlorite NaClO2, Sulphuric acid H2SO4 and more.
Refractive Index range, standardFull range, nD1.3200…1.5300 (corresponds to 0…100% b.w.), sapphire prism
Refractive Index range, optionnD 1.2600…1.4700, sapphire prism.
AccuracynD± 0.0002, typically corresponds to ± 0.1% b.w.
Repeatability nD± 0.0001, typically corresponds to ±0.05% b.w.)
Speed of response1s undamped, damping time selectable up to 5 min
Patented CORE-OpticsNo mechanical adjustments and digital measurement with 3648 pixel CCD element, sodium D-line light emitting diode (LED), built-in Pt-1000 temperature sensor
Temperature compensationAutomatic, digital compensation
Instrument verificationWith standard nD liquids and the documented procedure (ISO 9000)
Ambient temperatureSensor: -20 °C…45 °C (-4 °F…113 °F); Indicating transmitter: 0 °C…45 °C (32 °F…122 °F)
Process temperature-20 °C…130 °C (-4 °F… 266 °F)
Sensor protection classIP67, Nema 4X
Approvals for hazardous locations-20 °C…130 °C (-4 °F… 266 °F)
Sensor protection classNon-Sparking/Non-Incendive version: ATEX certified for Zone 2 area, Ex II 3 G, EEx nA IIC T4 Gc; FM certified for Class I, Div. 2, Groups A, B, C & D hazardous locations, T6; CSA certified for Class I, Div. 2, Groups A, B, C & D, T4; IECEx certified, Ex nA IIC T4 Gc
Intrinsically safe version: ATEX certified for Zone 0 area, Ex II 1 G, EEx ia IIC T4 Ga; FM certified for Class I, Div. 1, Groups A, B, C & D, T4 (for U.S.A. and Canada); IECEx certified, Ex ia IIC T4 Ga
Approval for electrical safety-20 °C…130 °C (-4 °F… 266 °F)
Sensor protection classcCSAus certified, Equipment Class I, Poll. Deg. 2 / Transmitter, Poll. Deg. 3 / Sensor, Install. Cat. II
SENSOR PR-23-WProcess connection with ETFE (Ethylene tetrafluoroethylene) lined Saunders (diaphragm) valve body 2″, 3″ or 4″; valve body material Graphite cast iron
Saunders body process connectionDIN-flange DN50 PN 16/DIN-flange DN80 PN 16/DIN-flange DN100 PN 16/ANSI-flange 4″ 150 lbs/ANSI-flange 3″ 150 lbs/ANSI-flange 2″ 150 lbs / JIS-flange 10k 50A/ JIS-flange 10k 80A/ JIS-flange 10k 100A
Sensor wetted partsETFE (Ethylene tetrafluoroethylene) lining, prism gasket Teflon® PTFE, prism sapphire, O-ring Kalrez, adaptor sapphire
Sensor weightwith 2″ Saunders body 15 kg (33 lbs)/3″ 26 kg (57 lbs)/4″ 33 kg (73 lbs)
Process pressuremax. 10 bar (145 psi)
SENSOR PR-23-MProcess connection with Thread G1/2″ (F) or Thread NPT 1/2″ (F)
Sensor wetted partsTeflon® PTFE or Kynar® PVDF (Polyvinylidenefluoride), prism gasket Teflon® PTFE, prism sapphire, O-ring Kalrez, adaptor sapphire
Sensor weight5.5 kg (12 lbs)
Display320×240 pixel graphical LCD with LED backlight, keypad with 8 membrane keys
Current outputTwo independent current outputs, 4-20 mA, max. load 1000 Ohm, galvanic isolation 1500 VDC or AC (peak), hold function during prism wash
Fieldbus and industrial Ethernet connectivityThrough Fieldbus converter to Modbus/TCP, Modbus RTU and Ethernet/ IP networks
PowerAC input 100-240 VAC/50-60 Hz, optional 24 VDC, 30 VA
Alarms/Wash relaysTwo built-in signal relays, max. 250 V/3 A
Sensor connectivityOne or two sensors can be connected to one DTR. Sensors independent with own parameter sets and usable in different applications. Two current outputs configurable independently to indicate process concentration or temperature of either sensor
Indicating transmitter weight4.5 kg (10 lbs)
Transmitter protection classPolycarbonate enclosure IP66, Type 4X (indoor use); AISI 304 Stainless steel enclosure IP66 (Indoor use)
INTERCONNECTING CABLEIEC 61158-2 compliant two-wire cable
Interconnecting cable lengthStandard 10 m (33 ft), max. 200 m (660 ft). Cable fittings to Indicating transmitter: European cable glands M20x1.5 or US conduit hubs

Source: Vaisala K-Patents