51451326-504 | Honeywell | Low-Temperature pH Probe

Honeywell 51451326-504 Low-Temperature pH Probe

The Honeywell 51451326-504, also cataloged as a low‑temperature pH probe, serves as a dedicated electrochemical sensor for aqueous process monitoring in chemical, water treatment, and pharmaceutical systems.

Hardware Specifications

4-20 mA HART Loop Protocol

When paired with Honeywell transmitters (UDA2182, APT2000, APT4000, DirectLine series), the probe integrates into:

• 4‑20 mA HART loop protocol conversion for distributed control systems.
• Channel‑to‑channel isolation across multiple probes in shared manifolds.
• Cold junction compensation (CJC) applied in transmitter electronics, ensuring stable readings.
• FOUNDATION Fieldbus / Profibus PA connectivity supported via associated Honeywell controllers.

Frequently Asked Questions (FAQ)

Q: What is the maximum pressure rating? A: The probe supports up to 5 bar (72.5 psi) in aqueous process environments.

Q: How fast does the probe respond? A: Response time is under 30 seconds, ensuring rapid stabilization during process changes.

Q: Which controllers are compatible? A: The probe connects directly to Honeywell UDA2182, APT2000, APT4000, and DirectLine series instruments.

Field Installation Guidelines

• Install probe in continuous wetting conditions to maintain electrode stability.
• Avoid routing cable parallel to high‑voltage conductors to reduce induced noise.
• Maintain immersion depth sufficient to cover the reference junction.
• Rinse electrode with clean water before insertion to prevent contamination.
• Ground associated transmitters to plant earth to minimize offset errors.
• Verify calibration after thermal equilibrium is reached in low‑temperature environments.