China Water TDS Sensor Supplier & Pricelist

Total Dissolved Solids (TDS) refers to the cumulative mass of inorganic mineral salts and organic matter dissolved in water, expressed in milligrams per liter (mg/L) or parts per million (ppm). Sensors do not count dissolved particles directly; instead, they measure the flow of electrical current through dissolved ions (EC in μS/cm or mS/cm). The conversion is calculated using the formula: TDS (ppm) = Conductivity (μS/cm) × Conversion Factor.

Because different mineral species conduct electricity with varying mobilities, standard factors range between 0.5 (common for pure NaCl solutions and RO systems) and 0.7 (typical for agricultural runoffs and boiler waters). Our digital sensors allow field engineers to configure this multiplier or select automated non-linear polynomial conversion tables for exact chemical matches.

The cell constant (K = d / A, where d is the distance between plates and A is electrode surface area) dictates the sensor's measurement resolution and operational range:

• K = 0.01: Dedicated to ultra-pure water, WFI (water for injection), pharmaceutical loops, and thermal power plant condensate (0.001 – 20 μS/cm or 0.0005 – 10 ppm TDS).
• K = 0.1: Ideal for reverse osmosis permeate, drinking water supply, and light deionized streams (0.1 – 200 μS/cm or 0.05 – 100 ppm TDS).
• K = 1.0: The industry standard for surface water, municipal drinking distribution, cooling tower cycles, and general industrial process fluids (10 – 2,000 μS/cm or 5 – 1,000 ppm TDS).
• K = 10.0 or Toroidal Induction: Designed for brackish brine, seawater desalination feeds, and high-salinity industrial effluent (1,000 – 100,000+ μS/cm or up to 50,000+ ppm TDS).

Ion mobility in an aqueous solution increases with thermal excitation. Water conductivity typically rises by approximately 1.8% to 2.2% per degree Celsius increase, even though the actual mass concentration of dissolved solids has not changed. Without compensation, a process running at 50°C will show a falsely elevated TDS compared to room temperature (25°C).

All BOQU TDS sensors integrate precision PT100, PT1000, or NTC 10K thermistors located adjacent to the electrode tips. Internal firmware automatically normalizes all real-time readings back to the international reference baseline of 25°C using configurable linear or non-linear temperature compensation curves.

As a genuine manufacturer operating two facilities in Shanghai totaling 4,632 m², we maintain extreme manufacturing flexibility. Standard stock probes carry an MOQ of only 2 to 5 units for testing. For private-label OEM (laser-engraved customer logos, custom housing colors, specified cable materials such as PTFE or silicone, and tailored Modbus register maps), our standard MOQ is 50 units.

Standard lead times for catalog configurations are 3 to 7 working days, while custom OEM volume batches are reliably fulfilled within 14 to 21 business days with full batch calibration certificates.

Variable frequency drives (VFDs) and high-power aerator pumps in municipal plants generate severe harmonic common-mode electrical noise. BOQU digital IoT sensors incorporate optical and galvanic isolation barriers up to 2,500 V between the fluid-wetted sensor tip and the RS485 communication line.

Furthermore, internal grounding techniques and hardware filtering reject 50Hz/60Hz grid hum, allowing our sensors to run side-by-side with heavy motor cables inside crowded cable trays without transmission corruption.