Robust pH Screw Cap Probe


  • Measurement range pH 7.0-9.0
  • Robust fiber with threaded tip
  • Exchangeable Sensor Screw Caps
  • Precalibrated for plug & play measurements
  • For small amounts of stirred liquid

This robust pH screw cap probe represents a new generation of fiber-based pH sensors from PyroScience and a viable alternative to traditional pH electrodes. This new sensor format is composed of a robust cap adapter fiber with stainless-steel tip (10cm length, ø4mm) and a disposable plastic screw cap with integrated pH sensor. The pH sensor cap can be screwed on the threaded tip of the robust fiber. If worn out, keep the fiber and simply exchange the pH sensor cap and continue with your pH measurements. The PHROBSC-PK8 comes initially with 4 sensor caps. If more caps are required, an additional set of 4 pH sensor screw caps (PHSC-PK8) can be obtained. 

With this new sensor format, PyroScience aims to provide a more sustainable approach (reducing waste) and improve even further the user-friendliness of our sensors.

Our new precalibrated pH sensors can be used once without manual calibration in combination with a FireSting-PRO meter that enables pre-calibration pH measurements (older FireSting-PRO meters can be upgraded). Pre-calibration measurements are intended for single-use applications. After first use of the precal pH sensor, the sensor can be continued to use after a manual calibration (mandatory). For precision measurements in other applications, a manual 2-point calibration of the pH sensor must be performed before the measurement.

pH range 7.0-9.0 This sensor is specified for the pH range 7.0-9.0. For detailed specifications, see the respective pdf file in the Downloads tab.

Precalibrated pH measurements The pH sensor caps can be used once without a manual calibration. For precision pH measurements, a manual sensor calibration is mandatory before the measurement.

No reference electrode needed. Based on the optical sensing principle (REDFLASH technology), the pH value is measured directly on the sensor surface without a reference electrode.

Screw cap probe. For easy and sustainable renewing of the sensor after demanding applications. Replacement screw caps can be found under accessories. Tip diameter 4mm.

Optical isolation.This sensor type is equipped with an additional optical isolation protection layer. This layer reduces enhanced sensor aging and interference with the measurements in applications at high ambient light (e.g. direct sunlight, illuminated samples) and in fluorescing / light-sensitive samples.

Easy calibration. Calibration of the pH sensors is performed at pH 2 and pH 11 using our easy-to-use calibration capsules (PHCAL2 and PHCAL11). For detailed calibration recommendations, please refer to the manual in the downloads tab.

ST-connector. This connector is our standard sensor connector for sensor compatible PC-operated and handheld FireSting devices.

Standard stock item. This item is typically in stock and small numbers can be shipped quickly. This does not apply for larger amounts, which ship with standard delivery time.

Applications. To get an overview of potential applications and to see our sensors in action, please visit our Applications site!

Price List

Calibration Capsules (pH 2)


For obligatory acid calibration of optical pH sensors. Each capsule results in 100mL calibration solution (PU=10).

Calibration Buffer Capsules (pH 11)


For recommended basic calibration of optical pH sensors. Each capsule results in 100mL calibration buffer solution (PU=10).

Additional Sensor Screw Caps


Additional sensor screw caps for simple exchange of the pH sensitive sensor (PU = 4 pieces).

Every PyroScience pH meter with a ST-connector (lab devices) is compatible to this sensor. Use this link to get a list of all compatible meters. Select additional requirements to find the optimal meter for you and your application!


Exemplary Setup


Choose the multi-analyte FireSting-PRO (4 chan.) with the pH probe PHROBSC-PK8

  • 4 freely configurable optical channels
  • + oxygen & temp sensor support

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