Frequently Asked Questions

Minco Tech India Pvt. Ltd. is a Kolkata-based manufacturer of disposable thermocouple probes (MINTEMP), oxygen probes (MINOX), steel and slag sampler probes (MINSAMP), sublance probes, hydrogen measurement systems (HydroinS), combined 2-in-1 and 3-in-1 probes, MINTHERM display instruments, MI-866 handheld calibrators, compensating lead cable, and related accessories for the global steel industry. We have been manufacturing since 1990 — over 34 years — and produce 2 million+ probes per year from two facilities in Kolkata and Howrah.

Yes. Minco Tech India Pvt. Ltd. holds three ISO certifications: ISO 9001:2015 (Quality Management System), ISO 14001:2015 (Environmental Management System), and ISO 45001:2018 (Occupational Health & Safety Management System — Internal Auditor). Our thermocouple products comply with BS EN 60584-1 and BS EN 60584-2 for thermocouple calibration under the ITS-90 international temperature scale. We also carry the Make in India recognition.

We currently supply steel plants in India (TATA Steel, JSW, SAIL, NMDC, Jindal Steel & Power, MIDHANI, ESL Steel, Gerdau and others), the Gulf region (Saudi Arabia — Hadeed/SABIC; UAE — Emirates Steel, AGSI; Bahrain — SULB; Kuwait), North Africa (Algeria — Maghreb Steel; NASCO), Bangladesh (BSRM), and other Asia-Pacific markets. We export FOB Kolkata to any port worldwide on standard commercial terms.

Steel plants switching from European suppliers — such as Heraeus Electro-Nite or Celox — to Minco India typically achieve 30–50% savings on probe consumable costs. This comes from eliminating import duties, transcontinental freight, currency hedging risk (EUR/USD fluctuation), and the inherent lower cost of Indian manufacturing — with no compromise on accuracy or probe quality. Additionally, our lead times are 1–2 weeks versus 6–8 weeks from Europe, and our engineers provide direct plant-floor technical support rather than remote distributor service.

We operate two manufacturing units. Our Kolkata headquarters at 3 Pretoria Street, Unit 2G, Kolkata – 700071 handles administration, R&D, and assembly of precision probe components. Our Howrah manufacturing plant at J.L. No. 3, NH-6, Sulati, Dhulagarh, Howrah – 711302 handles larger-scale probe assembly, paper tube fabrication, and export packaging. Both facilities maintain in-house quality inspection with every production batch tested before dispatch.

A disposable (expendable) thermocouple probe is a single-use temperature sensor mounted on a cardboard lance tube and immersed into molten iron or steel. The probe tip contains two dissimilar metal wires (the thermocouple junction) encased in a quartz tube and protective paper or cardboard housing. When immersed, the junction generates a millivolt signal proportional to the metal temperature — based on the Seebeck thermoelectric effect. The signal travels through compensating cable to a display instrument where the temperature is shown in seconds. After one measurement the probe is discarded and a new one fitted.

MINTEMP Type S (Platinum / 10% Rhodium-Platinum): 1200°C – 1750°C, accuracy ±2°C — the most widely used type for BOF, EAF, ladle and tundish temperature measurement in steel plants.

MINTEMP Type B (Platinum-30% Rhodium / Platinum-6% Rhodium): 1200°C – 1800°C — preferred for ferro alloy furnaces, submerged arc furnaces, and applications where temperatures consistently exceed 1750°C.

Both types are calibrated to ITS-90 and comply with BS EN 60584.

A stable temperature reading appears within 2–5 seconds of immersion. The correct procedure is: (1) Insert the probe into the melt at 300–400 mm below the metal surface. (2) Hold steady — do not touch the furnace wall or ladle lining. (3) Read the stable peak temperature on the instrument. (4) Withdraw after no more than 5 seconds total immersion — exceeding this will burn out the hot junction and damage the lance. (5) Discard the used probe tip and fit a new one for the next measurement.

Yes — full drop-in compatibility. MINTEMP thermocouple tips are dimensionally identical to Heraeus Electro-Nite, Celox, and other international standard probes. They fit the same lance tubes, generate the same millivolt output, and work with all existing instruments without modification. Our team can match any custom lance diameter or connector type. Simply provide us with a sample probe from your current supplier, or the manufacturer and model number, and we will manufacture an exact replacement at significantly lower cost.

Common causes of inaccurate thermocouple readings and how to fix them:

• Immersion into slag layer — always break through the slag and immerse into clean metal
• Touching furnace wall or lining — immerse vertically, away from walls
• Immersion too long (>5 seconds) — the hot junction burns out, causing erratic readings
• Wrong compensating cable type — Type S probe requires Type S cable; mismatched cable introduces cold-junction error
• Kinked or damaged cable — inspect cable regularly; replace damaged sections
• Instrument not calibrated — verify with certified temperature reference regularly
• Damp or wet probes — store probes in dry conditions; discard probes that have been exposed to moisture

MINTEMP probes have a shelf life of 24 months from the manufacturing date when stored correctly. Storage requirements: dry environment (relative humidity below 70%), temperature between 10°C and 40°C, away from direct sunlight, stored horizontally in original sealed cartons. Probes exposed to moisture, rain, or high humidity should be discarded — moisture degrades the quartz tube protection and can cause premature probe failure or measurement errors. Always use probes on a first-in, first-out (FIFO) basis.

Active oxygen (oxygen activity, aO) is the dissolved oxygen in liquid steel that is free to react with de-oxidants, carbon, and other elements. It is not the same as total oxygen content. Active oxygen measurement is essential for: determining end-of-blow in BOF converters (along with carbon and temperature), calculating the correct quantity of aluminium or silicon de-oxidant to add, predicting steel cleanliness (oxide inclusions directly correlate with high oxygen activity), and controlling steel grade specifications. Even a small deviation — adding too little de-oxidant — leaves excess oxygen causing blowholes and surface defects; too much wastes expensive alloys and increases inclusion counts.

MINOX High PPM — designed for primary steel making where oxygen activity is high (200 – 1000+ ppm). Used in BOF converters at end-of-blow, EAF furnaces, and initial ladle tapping. The sensor cell is optimised for high oxygen concentration accuracy.

MINOX Low PPM — designed for secondary metallurgy after de-oxidation, where oxygen activity has been reduced to the range 1 – 200 ppm. Used in ladle furnaces (LF), RH/DH vacuum degassers, and tundishes for premium steel grades. Using a High PPM probe in a Low PPM application will result in inaccurate readings at the low end of the range, and vice versa.

The MINOX oxygen probe delivers a stable electrochemical oxygen reading within 4–6 seconds of immersion. The integrated Type S thermocouple inside the probe simultaneously delivers a temperature reading in the same immersion — so you get both temperature + active oxygen in a single 5-second dip. This is a significant advantage over separate sequential measurements, saving valuable heat time and reducing lance consumable cost.

MINOX oxygen probes are compatible with all major steel making units:

• BOF / LD / BOP Converter — end-blow oxygen and temperature (High PPM)
• Electric Arc Furnace (EAF) — end-of-melt oxygen measurement (High PPM)
• Ladle Furnace (LF) — post de-oxidation oxygen control (Low PPM)
• RH / DH Vacuum Degasser — ultra-clean steel oxygen verification (Low PPM)
• Tundish — continuous casting process control (Low PPM)
• OBM / Q-BOP / KOBM Converters — bottom-blown converter variants (High PPM)

MINSAMP is Minco India's range of immersion sampler probes that collect a small volume of liquid steel or slag for laboratory spectrometric analysis. After rapid solidification inside the probe during immersion, the collected disc-shaped metal sample is sent to the laboratory for OES (optical emission spectrometry) analysis to confirm steel chemistry — carbon, sulphur, phosphorus, manganese, silicon, and all alloying elements. This enables the steelmaker to verify the heat is within grade specification before tapping, avoiding costly off-grade corrections or scrapped heats.

Single-chamber samplers collect one steel disc sample for chemical analysis — the standard design for most BOF and ladle sampling applications.

Double-chamber samplers collect two samples simultaneously in a single immersion: one steel disc and one slag sample. This is useful when both steel chemistry and slag basicity/composition need to be analysed at the same point in the heat.

ULC (Ultra-Low Carbon) samplers are specially engineered for collecting samples from Ultra-Low Carbon steels (IF steels, electrical steels, deep drawing grades). The sample chamber is nitrogen-purged before and during immersion to prevent atmospheric carbon pick-up, which would falsely elevate the measured carbon content. Standard samplers are not suitable for ULC grades — the carbon pick-up error can exceed the entire specification limit.

A sublance is a mechanised lance system permanently installed on a BOF converter that can insert and withdraw probes automatically while the oxygen blow is still in progress — without tilting the converter. This allows mid-blow and end-blow measurements that would be impossible with a manual hand lance. Sublance probes are multi-functional, typically combining temperature measurement, oxygen activity measurement, carbon estimation (via thermal analysis of a solidification curve), and steel sampling — all in a single probe immersion. This enables dynamic control of the blow, reducing re-blow rates and improving first-hit performance. Minco India manufactures sublance probes compatible with all major sublance installations.

Celox is a trademarked brand name from Heraeus Electro-Nite for a range of combined oxygen + sampler probes that measure oxygen activity while simultaneously collecting a steel sample. Minco India manufactures compatible probes that perform the same dual function — measuring oxygen electrochemically and collecting a sample disc — and are dimensionally compatible with Celox lance systems. Our Celox-type probes are a direct replacement at significantly lower cost.

Dissolved hydrogen in liquid steel causes severe metallurgical defects upon solidification. As steel solidifies, hydrogen solubility drops dramatically and the excess hydrogen precipitates as: hairline cracks (flaking) in heavy forgings, rails, and thick plate; hydrogen-induced cracking (HIC) in pipeline steels in sour service environments; and porosity/blowholes in castings. These defects are especially dangerous in safety-critical applications — rail, pressure vessels, forgings, and line pipe. The maximum acceptable hydrogen level varies by grade (typically 1.5–4 ppm) and the only reliable way to confirm compliance before casting is in-situ ladle measurement using a hydrogen probe.

The HydroinS system uses a disposable immersion probe lowered into the ladle of liquid steel. Inside the probe, a controlled flow of nitrogen carrier gas bubbles through the melt and equilibrates with the dissolved hydrogen in the steel. The hydrogen partial pressure in the exiting gas is measured by a precision solid-state sensor in the HydroinS analyser unit. Using Sievert's law (which relates dissolved gas content to partial pressure and temperature), the analyser calculates the dissolved hydrogen content in ppm. A complete measurement — immersion to reading — takes less than 60 seconds, making it practical for routine ladle-by-ladle quality control.

The HydroinS system measures dissolved hydrogen in the range of 0.5 ppm to 15 ppm — covering the full range from vacuum-degassed ultra-clean steel through to undegassed EAF heats. The system is particularly valuable in the 1–4 ppm range where decisions about additional degassing cycles are made. Measurement accuracy is typically ±0.2 ppm at the low end of the range. A combined temperature reading from the integrated thermocouple is also provided with each hydrogen measurement.

HydroinS probes are used at the ladle stage — typically: before degassing (RH/DH/VD) to confirm baseline hydrogen level and set degassing parameters; after degassing to verify the steel has reached the target hydrogen content before casting begins; and at continuous caster tundish level for critical grades. Common applications include rail steel, forging steel, line pipe (X-grade), and any other hydrogen-sensitive grades where the customer specification includes a maximum hydrogen limit.

Minco India manufactures two instrument types. The MINTHERM series are large-format digital display units for fixed installation on furnace platforms and pulpits — they accept the millivolt signal from the thermocouple or oxygen probe via compensating cable and display the temperature and/or oxygen reading clearly for operators at distance. The MI-866 is a portable handheld digital calibrator available in rugged metal body and lightweight plastic body versions — used for field measurement, instrument verification, and commissioning. All Minco instruments are compatible with all standard Type S and Type B thermocouple and oxygen probe signals from any manufacturer.

Compensating cable (also called thermocouple extension lead or MI cable) carries the millivolt signal from the probe at the lance tip to the measurement instrument in the control room or on the platform. It must be made from alloy pairs that closely match the thermoelectric output of the thermocouple type being used — Type S probes require Type S compensating cable. Using the wrong cable type creates a spurious additional EMF at the cable-to-instrument connection (the reference junction), introducing a systematic temperature error that can be 20–100°C or more. Minco India supplies matched compensating cable for all thermocouple types, armoured for furnace-platform durability, in custom cut lengths.

The fastest route is to complete the enquiry form on our Contact page — specify the product type, probe variants, estimated annual quantity, current supplier, and your delivery port. Alternatively email sales@mincoindia.com or WhatsApp us at +91 98840 22820. Our team responds within 24 hours with a technical quotation including full specifications, pricing, and lead time. For first-time customers we offer a free sample trial shipment so your metallurgical team can validate performance before committing to a supply contract.

Standard product variants are dispatched within 5–10 working days from our Kolkata/Howrah plants. For customers on scheduled supply contracts, we hold buffer stock enabling 1–2 week door-to-port delivery anywhere in Asia, the Gulf, or Africa. Custom dimensions or special-specification probes being manufactured for the first time require approximately 3–4 weeks for production tooling and first-batch manufacturing. Emergency or breakdown requirements can often be handled with 3–5 day dispatch for in-stock standard products.

For trial orders from new customers, we supply sample quantities (typically 1–2 cartons of 50–100 probes per type) at no minimum order requirement — we want you to test performance before committing. For regular supply, minimum order quantities start at one standard carton per probe type per shipment. Annual contracts with quarterly scheduled deliveries attract the best pricing and guaranteed availability. Contact our sales team for specific MOQs for your required product mix.

Yes — custom dimensions are a standard service. We regularly manufacture probes to match specific lance tube outer diameters (from 10mm to 25mm), immersion depths, cap configurations, and connector types. Our engineers can visit your plant to measure your lance system directly, or you can courier us a sample probe from your existing supplier. We will reverse-engineer it and manufacture dimensionally identical replacements. Custom probe development has a one-time tooling lead time of 3–4 weeks; subsequent repeat orders are fulfilled on standard lead times.

Yes. Minco India's technical team provides: plant trial support — our engineers attend your facility to oversee first-use of new probe types, run comparative accuracy tests versus existing suppliers, and troubleshoot any issues; instrument calibration — on-site verification and calibration of MINTHERM instruments and MI-866 calibrators; operator training — best-practice immersion technique, probe storage, and reading interpretation for your furnace operators and metallurgists. We also provide ongoing remote support via WhatsApp and phone for day-to-day technical questions. Contact us at sales@mincoindia.com to schedule a visit.

We invoice in Indian Rupees (INR) for domestic customers and US Dollars (USD) or UAE Dirhams (AED) for export customers. For new customers, we typically require advance payment or a Letter of Credit (LC). Established regular customers are offered credit terms of 30–60 days. Bank wire transfer (TT), LC, and major commercial banking instruments are all accepted. Contact our accounts team alongside your technical enquiry and we will advise the most suitable payment structure for your procurement process.