FloraPulse + METER ZL6
For years the answer to “can I run FloraPulse sensors on my METER ZL6?” was no. METER’s loggers have SDI-12 terminals, but they are built to recognize METER’s own sensors, so a third-party probe plugged into a ZL6 simply never appeared. Researchers and growers who already owned ZL6 loggers had to buy a second datalogger to add stem water potential to a site that was already instrumented.
That is no longer the case. The FloraPulse SDI-12 box now has a ZL6 Compatibility Mode. In this mode the box presents itself to the logger as a METER sensor, so the ZL6 detects it on the port automatically and records it exactly like any METER probe — no custom programming, no separate logger, no extra field visit.
The short version
Plug a FloraPulse SDI-12 box into a spare ZL6 port and the logger finds it on its own. Readings flow into ZENTRA alongside your soil and weather data. You need newly ordered SDI-12 boxes (the mode cannot be added to boxes already in the field) and a small adapter pigtail. Typical lead time is about two weeks.
Which Loggers Work
ZL6 Compatibility Mode works with any METER datalogger that reads the MPS-6 water potential sensor. In practice that covers the current ZL6 and the older Decagon-era loggers still in service at a lot of research stations.
| Datalogger | Works with FloraPulse? | How |
|---|---|---|
| METER ZL6 | ✅ Yes | SDI-12 box in ZL6 Compatibility Mode + adapter pigtail |
| METER / Decagon Em50 | ✅ Yes | Same — reads the MPS-6 protocol |
| METER Em60 / EM60G | ✅ Yes | Same — reads the MPS-6 protocol |
| Campbell Scientific CR300, CR1000X, CR6, CR1000 | ✅ Yes | Standard SDI-12, or analog probes straight into differential channels |
| Other SDI-12 loggers EnviroPro, Adcon, In-Situ, Ranch Systems… | ✅ Yes | Standard SDI-12 mode — no persona needed |
Campbell Scientific loggers remain fully supported and are still what we use ourselves. ZL6 Compatibility Mode exists so that a site already built around METER hardware does not need a second logger just to add plant water status.
What You Need
- FloraPulse microtensiometer probes — one per measurement point. See how the sensor works.
- A FloraPulse SDI-12 box per probe, ordered with ZL6 Compatibility Mode. The box holds that probe’s calibration and outputs a finished water potential reading — you are not post-processing raw voltages.
- An adapter pigtail (3.5 mm stereo plug to bare leads) to go from the box terminals into the ZL6’s sensor port. We supply this.
- A free port on the logger. The box runs on the power the ZL6 already provides — no separate supply, no battery to service.
Two Things To Know Before You Order
1. It requires newly ordered SDI-12 boxes
ZL6 Compatibility Mode lives in the box’s firmware and is built in at manufacture. Boxes already in the field cannot be updated to add it — there is no field upgrade path. If you have FloraPulse SDI-12 boxes deployed today and you want to move them onto a METER logger, you will need new boxes. Tell us when you order that the boxes are for a METER logger and we will ship them configured and ready.
2. ZENTRA will label the reading “soil matric potential”
Because the box identifies itself as a METER water potential sensor, ZENTRA charts it under that sensor’s name and units. The number is stem water potential, reported in kPa. The chart label cannot be changed from your side, so it is worth telling everyone on the project. The value itself is correct and fully calibrated — only the label is borrowed.
Converting is simple: divide kPa by 100 to get bar. So −1500 kPa is −15 bar, and −800 kPa is −8 bar. The accompanying “soil temperature” channel is the probe’s own temperature reading.
Reading The Numbers
Stem water potential is always negative — it is a tension, the pull the tree exerts to draw water up from the soil. The more negative the number, the harder the tree is working and the more stressed it is. Here is roughly how the kPa values you will see in ZENTRA translate for most tree crops and vines:
| In ZENTRA (kPa) | In bar | Typical interpretation |
|---|---|---|
| −200 to −600 | −2 to −6 | Well watered, little to no stress |
| −600 to −1200 | −6 to −12 | Mild to moderate stress — often the target band for deficit irrigation |
| −1200 to −1800 | −12 to −18 | Strong stress |
| Below −1800 | Below −18 | Severe stress |
The right target depends heavily on crop, growth stage and objective — hull split in almonds is a different question from berry ripening in wine grapes. Our scientist resources and the published research library go into the crop-specific thresholds, and our team is happy to talk through yours.
Common Questions
Does this need special programming on the ZL6?
No. The logger scans the port, finds the sensor and starts recording. Setup is the same as plugging in any METER probe.
Can I still use the box on a Campbell logger later?
Yes. Compatibility mode is switchable — the box can be returned to standard FloraPulse SDI-12 at any time, so the same hardware moves between a METER logger and a Campbell as your deployment changes.
How many probes can one logger take?
One FloraPulse box per ZL6 port. Beyond that you are bounded by the logger’s port count rather than by anything on our side.
Do I need a FloraPulse subscription or dashboard?
No. Running on your own logger, the data is yours in ZENTRA and no FloraPulse subscription is required. Our own cellular datalogger and dashboard remain an option if you would rather have thresholds, alerts and crop-specific guidance built in — see why FloraPulse.
Is this endorsed by METER?
No, and we do not claim it is. ZL6 Compatibility Mode is our own engineering, built so our customers can use hardware they already own. It is not a METER product and is not supported by METER.
Already Have ZL6 Loggers In The Field?
Then adding continuous stem water potential to those sites just got considerably cheaper — you are buying sensors, not a second logging network. Tell us how many ZL6 ports you have free and what you are growing, and we will put together a quote and the wiring details for your setup. Lead time is typically about two weeks.
More on using FloraPulse with your own equipment
How It Works · For Scientists · Research & Manuals · FAQ · Find a Distributor
METER, ZL6, ZENTRA, TEROS, MPS-6 and Em50 are trademarks of METER Group, Inc. Decagon Devices is now part of METER Group. Campbell Scientific is a trademark of Campbell Scientific, Inc. FloraPulse is not affiliated with, endorsed by, or sponsored by METER Group. Product names are used solely to identify equipment our sensors are compatible with.