Part of Honeywell’s product range for pH measurement, the DirectLine® DL421 pH Transmitter Sensor combines the latest in microelectronics technology with the proven performance of Honeywell’s sensing technologies, in a unique modular design, for accurate pH monitoring and control.​​

What Is It?

DirectLine DL421 pH Transmitter modules are next-generation analytical transmitters that easily interface with Honeywell’s packaged solutions for accurate pH measurement.

The pH transmitter eliminates pre-amps in pH applications and is connected directly to a Durafet II, Durafet III, DL2000 glass or HPW7000 pH electrodes. This makes the pH transmitter highly cost effective as it is easy to install, start-up, operate and maintain.

Designed to be intrinsically safe, this analytical transmitter’s corrosion-resistant sealed plastic enclosure makes it ideal for harsh environments where moisture, dust and chemicals may be prevalent. A remote mounting option for submersion or special mounting applications connects the electronics module to the pH electrode via a cable. The module can be mounted on a 2-inch pipe, wall or DIN rail.​

How Does It Work?

The DirectLine DL421 pH monitoring and control system provides unequaled savings during installation, startup, operation and maintenance.

This pH monitoring and control system comprises an electronics transmitter module directly connected to an electrode which can be mounted integrally to the analytical transmitter or remotely, eliminating the need and added cost of a separate analyzer or pH transmitter.

An LCD display gives local readout of process pH that is also re-transmitted through the 4-20 mA loop powered cable. A simple three button interface makes set-up and configuration fast and easy.​

What Problems Does It Solve?

Honeywell’s DirectLine DL421 pH Transmitter offers accurate and cost-effective analytical measurement of pH, resulting in efficient control of process systems. In addition, remote or direct connectivity makes this pH monitoring and control system easy to fit into the process environment. ​

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