Description
The Yokogawa SC200S is a microprocessor-based, intrinsically safe two-wire conductivity and resistivity transmitter. It provides continuous online measurement of solution conductivity or resistivity in chemical, pharmaceutical, power generation, and water treatment applications, specifically designed for hazardous area installations utilizing approved safety barriers.
Product Specifications
| Parameter | Value |
| Manufacturer | Yokogawa |
| Model / Part Number | SC200S (Intrinsically Safe Version) |
| Device Type | Two-Wire Conductivity / Resistivity Transmitter |
| Input Signal | AC voltage excitation to electrode; receives proportional current signal |
| Output | 4 to 20 mA DC analog signal with superimposed digital diagnostics/alarm states |
| Power Supply | 24 V DC (supplied via dedicated safety barrier for hazardous locations) |
| Explosion-Proof Rating | Intrinsically safe design (requires certified safety barrier such as BARD400) |
| Operating Environment | Humidity 45 to 85% RH; Altitude up to 1,000 m |
| Lifecycle Status | Discontinued by manufacturer (Discontinuation Date: May 31, 2005) |
| Condition | Factory Surplus / Tested Refurbished / Used (dependent on inventory source) |
| Availability | Sourced through legacy automation and spare part inventory channels |
| Warranty | 12 Months Standard Replacement (varies by supplier) |
Note: Listed price is indicative, not final. Price subject to market conditions; contact us for a firm quote.
Technical Overview and Deployment Constraints
The SC200S processes square-wave AC voltage applied to contacting-type conductivity detectors, translating the measured ionic concentration into a standard 4–20 mA loop current. Because this variant is certified for intrinsically safe (IS) hazardous locations, strict loop resistance, capacitance, and inductance limits apply to the external field wiring.
When replacing or maintaining an installed SC200S unit, verify that the associated safety barrier (such as the BARD400) matches the loop loop-power parameters. Ensure terminal blocks are properly sealed and grounded according to the original installation manual to maintain hazardous area compliance and avoid ground-loop-induced measurement drift.
Frequently Asked Questions
Q: Is the Yokogawa SC200S currently supported by the manufacturer? A: No, this product was officially discontinued by Yokogawa on May 31, 2005. Replacement units are typically acquired through verified surplus inventory, refurbished channels, or migrated to modern Yokogawa FLXA series transmitters.
Q: What is the difference between the SC200G and the SC200S? A: The SC200G is the standard non-explosion-proof version intended for general environments, whereas the SC200S is certified for intrinsically safe hazardous locations and requires a safety barrier
