MTT MS3004 Terminal Block Type High-Level Signal Conditioner (Isolator)

We had an enquiry from a customer who wanted to split an existing 4 to 20mA loop to feed a second display without disturbing the reading on the original controller. Their concern was that tapping straight into the loop might introduce noise or upset the calibration on the primary instrument.

This looks simple, but wiring a second device straight into a live current loop is not something we would recommend doing directly. Any extra load on the loop changes its resistance, and if the two devices don’t share a truly isolated ground, you end up with a ground loop that shows up as drift or noise on both ends. In actual application, plants running VSDs, welding sets, or heavy switching gear nearby make this worse.

For this, we would normally recommend the MTT MS3004, a terminal block type signal conditioner and isolator. It accepts a wide range of DC current or voltage inputs and re-issues them as a clean, isolated 4 to 20mA or voltage output, with full isolation between input, output, and power supply. That isolation is what lets you split or repeat a signal safely, without loading down or disturbing the original loop. It mounts on DIN rail right at the panel, has field-adjustable zero and span for on-site calibration, and a fast-response /K option is available where response time under load actually matters.

Before we quote, we would normally check the exact input signal range from the existing loop, the output range the second device expects, and whether a fast-response version is needed for your application. Hope this helps — let us know your signal details and we can confirm the right model together.