How is fluorescence different from polarographic DO sensors?

Polarographic probes consume oxygen electrochemically and rely on an electrolyte-filled membrane that ages: typically re-membraned and re-filled every 1-3 months, with drift in between. Fluorescence quenching consumes no oxygen and needs no membrane — only the fluorescent cap is replaced every 1-2 years as a consumable, so maintenance burden and drift drop dramatically.

What about biofouling in ponds?

Biofilm growth on the sensing surface is the main drift source in pond water. The Y504-A can be fitted with an automatic wiper cleaning device that scrubs the sensor surface on schedule; the silicone brush is a consumable replaced on the maintenance cycle. More: https://www.kantangren.com/knowledge/sensor-biofouling-auto-clean-en

How often must it be calibrated?

Factory two-point calibration (zero-oxygen + saturated) is stored in flash and auto-loaded at power-on, so routine manual calibration is not required. A one-key air-saturation check every 3-6 months is recommended, and recalibration is required after replacing the fluorescent cap.

Y504-A Fluorescence Dissolved Oxygen Probe

Model: Y504-A | Fluorescence quenching | IP68 titanium | RS485 Modbus RTU

The Y504-A is the sensing core of the TAYKEE system — an online dissolved oxygen probe built for pond aquaculture. It stays submerged 24/7, feeding live DO readings to the 4G controller that drives aeration. Its membrane-free, electrolyte-free design exists to kill the classic pain of pond sensing: drift, membrane changes and unreliable data.

What it solves

Invisible pre-dawn crashes: grab-bottle sampling gives one instant; the 2–5 a.m. DO minimum is exactly what it misses. The Y504-A records continuously;
Heavy polarographic upkeep: membranes age, electrolyte depletes, data drifts — fluorescence needs neither;
Biofouling drift: algae and bacteria coat any probe in pond water; an optional automatic wiper scrubs the sensor surface on schedule;
Data that goes nowhere: readings go straight over RS485 Modbus into the controller that starts, stops and speed-controls aerators on the spot.

How it works

A fluorescent dye on the probe tip is excited by blue light and emits red; oxygen molecules quench that emission — more oxygen, less fluorescence. Measuring the phase/intensity shift yields dissolved oxygen without consuming it and without any electrolyte. The signal rides the RS485 Modbus RTU bus to the TAYKEE 4G gateway, which runs the local DO closed loop and uploads curves and alarms to the cloud platform.

Key specifications

Principle	Fluorescence quenching (membrane-free, no electrolyte)
Range	0 ~ 20 mg/L
Response time	30 ~ 60 s (T90)
Operating temperature	0 ~ 40 °C
Ingress protection	IP68, continuous submersion
Body	Titanium, corrosion resistant
Interface	RS485 · Modbus RTU (direct to TAYKEE 4G controller)
Supply	12 V DC (from controller/system bus)
Salinity compensation	0 ~ 40 ‰ software compensation for brackish ponds
Consumables	Fluorescent cap every 1–2 years; wiper brush every 6–12 months when equipped

Where it fits

Fish ponds — carp, tilapia, sea bass and other intensive fish farms on 24/7 DO watch;
Shrimp ponds — whiteleg shrimp: molting stages are oxygen-critical, continuous monitoring is a must;
Crab ponds — benthic animals, bottom-layer DO with proper probe depth;
High-density and hatchery operations — where the safety margin is thinnest.

Installation

Position: away from direct aerator flow and feeding areas, where water best represents pond-wide DO;
Depth: below normal waterline in the inhabited layer; deeper placement for benthic species;
Mount: buoy or bracket suspension — never resting in mud; see the full installation guide;
Wiring: cable routed and protected along the dike (waterproofing, aging protection), terminated on the controller RS485 bus.

In the TAYKEE system

Plug-and-play inside the stack: one RS485 bus is dedicated to sensing; after Modbus address assignment the TK-4G-GW gateway polls the probe, runs the DO threshold loop locally (start aerators below the safety line, slow down after recovery) and streams curves and graded alarms to the cloud. One gateway pairs with 1–2 probes and multiple aeration channels; scale by cascading.

FAQ

Does "maintenance-free" mean never calibrate?: Factory two-point calibration is stored in flash and auto-loaded, so no routine manual calibration is needed. We recommend a one-key air-saturation check every 3–6 months (lift the probe, press once), and recalibration is mandatory after fluorescent-cap replacement.
How many probes per pond?: A probe reads its local water. Typical intensive ponds are covered by 1–2 probes placed per the installation guide; larger or stratified ponds need more points, decided at survey.
Can it run in brackish or marine ponds?: It supports 0–40 ‰ software salinity compensation and the titanium body resists corrosion; for marine/brackish sites we pair it with the TK.AS.8in1 (salinity 0.01–25%) during solution design and confirm cleaning cycles at survey.