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InPro 4800(i) / InPro 4881i
Sensor pH for the Harshest Process Conditions
The InPro 4800 family, with substantially prolonged operational life in the presence of aggressive chemicals
or at high operational pressures, significantly reduces electrode maintenance and frequency of
The probes offer reliable measurements in oxidizing media, strong acid or alkali solutions,
sulfide-bearing media, etc.
The InPro 4881i features a rugged titanium shaft and its flat pH membrane is
protected by a PEEK cap providing a robust solution for achieving process safety in challenging industrial


The InPro 4800 (i) and InPro 4881i electrodes, with very long diffusion path using two electrolyte chambers,
provide the following advantages:
• Extended lifetime:
–Very high resistance to oxidizing media, solvents and acid or alkali solutions.
–Highly resistant to any effects from poisoning ions, e.g., sulfide etc., due to a long diffusion path, and
a dirt-repelling annular junction (PTFE).
–Pressure-compensated diffusion path enables operation at particularly high (process) pressures.
–Designed for high temperatures.
• Available with the option of an auxiliary platinum electrode for Solution Ground (SG): The platinum-plated
surface enables redox (ORP) measurement (InPro 4800 (i) only) and advanced sensor diagnostics, as
well as preventing measurement errors due to ground potentials
ISM® technology provides the following advantages:
–Swift exchange of pre-calibrated sensors at the measuring point with the Plug and Measure feature.
–Advanced sensor self-diagnostics.
–Predictive maintenance functions.
–Monitor the ageing of the sensor in real time with the Dynamic Lifetime Indicator.
–Adaptive Calibration Timer determines when the next calibration will be due.
InPro 4881i robust construction with titanium shaft
Featuring a titanium shaft and a stainless steel thread, the InPro 4881i has been designed to withstand not
only the most aggressive process conditions, but also the common everyday knocks in industrial sites.

Technical data of the InPro 4800 (i) & InPro 4881 i

pH range

InPro 4800 (i): 0 – 14 pH

InPro 4801 (i), InPro 4802 (i): 1 – 14 pH

InPro 4881 i: 1 – 14 pH


– 5 to 130 °C (23 to 266 °F)


12 bar at 130 °C (174 psi at 266 °F)

Cable Connection

ISM: K8S; Analog: VP

Process Connection

Pg 13.5 thread

Reference system

Ag / AgCl system, pressure-compensated double gel-electrolyte chambers

Type of junction

Exterior: PTFE annular diaphragm

Interior: Non-flow ceramic diaphragm

Reference electrolyte



120 mm, 225 mm, 425 mm

Shaft diameter

12 mm

Shaft materials

InPro 480x (i): Glass; InPro 488x i: Titanium

Temperature sensor

ISM: Digital; Analog: Pt 100 or Pt 1000





pH membrane

Various by applications

Solution ground

InPro 480x (i): Platinum; InPro 488x i: Titanium


METTLER TOLEDO Quality certificate, Pressure Equipment Directive guidelines (PED) 97/23/EC ATEX: Ex ia IIC T6 / T5 / T4 / T3 Ga / Gb, FM: IS Cl. I,II,III Div 1, GR ABCDEFG / T6 EN 10204-3.1 (InPro 4881 i)


  • Technical Data
  • Datasheet
  • Instruction Manual