We have a high-temperature environment. What wireless sensors are rated to withstand extreme heat in a steel foundry?

In a steel foundry environment, deploying wireless sensors requires a clear distinction between two critical temperature zones: the process/measurement tip temperature (the extreme heat of molten metal or furnaces reaching up to 1,000°C to 1,600°C+) and the ambient/housing temperature where the wireless transmitter and electronics reside (subject to intense radiant heat, dust, vibration, and corrosive gases).

Because standard wireless electronics (batteries, RF transceivers, and digital logic) fail if exposed directly to ambient temperatures above 85°C (185°F) to 105°C, heavy-duty foundry solutions rely on remote-mount configurations (placing the transmitter away from the radiant heat zone using extension wire/armored cabling) or specialized heavy industrial housings with thermal barriers/heat sinks.

Top Industrial Wireless Sensor Systems for High-Heat Environments

1. Emerson Rosemount Wireless Temperature Transmitters Go to product viewer dialog for this item. (e.g., Rosemount 648 / 3145R Series Go to product viewer dialog for this item.)

• Design & Rating: Emerson provides industry-standard WirelessHART networks built for harsh process industries. For high-temperature or high-radiant areas, they use remote-mount sensor configurations.
• Temperature Capability: The transmitter housing handles standard industrial ambient bounds (typically up to -40°C to 85°C), but when paired with heavy-duty high-temperature or ceramic-insulated thermocouples via long extension cables/necks, the probe tip can measure extreme process heat well over 1,000°C.
• Why it fits foundries: Features heavy-duty cast aluminum or stainless-steel housings, IP66/IP67 ingress ratings, and robust WirelessHART mesh reliability that punches through heavy industrial interference and metal obstructions.

2. NCD Industrial Long-Range Wireless Thermocouple / RTD Transmitters (C1D2 Certified Options)

• Design & Rating: Offers modular long-range wireless mesh architecture (using secure 900MHz or international frequencies) with options for NCD C1D2 Certified Wireless Thermocouple Sensors rated for hazardous or heavy industrial environments.
• Temperature Capability: Uses specialized high-temperature probe extensions—such as Inconel 600 overbraided or Nextel ceramic fiber insulated thermocouple wires—allowing continuous sensing up to 980°C (1,800°F) and short-term service up to 1,090°C (2,000°F) at the tip, while keeping the battery-powered radio housing safely bracketed outside the direct radiant zone.
• Why it fits foundries: Extremely long transmission range (up to 2 miles line-of-sight), AES-128 encryption, and modular support for standard high-temp Type B, S, K, or R thermocouples.

• Design & Rating: Housed in NEMA 4X, IP65/IP67 weatherproof enclosures, built to withstand volatile industrial settings.
• Temperature Capability: Utilizes high-temperature RTD or thermocouple probes with lead lengths ranging from 3 feet up to 100 feet, allowing the probe to monitor critical high-temperature assets up to +370°C (+700°F) or higher depending on the probe variant, while the encrypted wireless transceiver stays in a cooler ambient zone.
• Why it fits foundries: Excellent for monitoring pre-heat ovens, annealing lehrs, cooling ducts, and auxiliary machinery where remote probing is practical.

Key Deployment Best Practices for Steel Foundries

• Remote Mounting is Mandatory: Never mount the wireless radio/enclosure directly onto a hot surface or in the direct line of sight of open molten metal radiant heat. Use extended armored or ceramic-beaded thermocouple leads (3m to 10m away) to locate the transmitter behind structural shielding or further down support columns.
• Material Selection for Probes: Standard stainless-steel sheaths will oxidize or melt near liquid steel or high-draw furnaces. Specify Inconel 600 Go to product viewer dialog for this item. , ceramic-sheathed, or specialized noble-metal thermocouples (Type S or B) for extreme process points.
• Wireless Frequency Considerations: Steel foundries are dense with moving cranes, large structural steel beams, and electromagnetic interference from induction furnaces. Opt for robust industrial mesh protocols (like WirelessHART or sub-GHz proprietary long-range mesh like 915MHz / 868MHz) rather than standard crowded 2.4GHz Wi-Fi when possible to prevent dropped packets.

To help narrow down the exact configuration you need, could you share:

• What specific asset or process are you monitoring (e.g., ladle pre-heater, furnace shell, exhaust duct, or cooling bed)?
• What is the approximate process temperature at the measurement point and the ambient temperature where the transmitter would sit?

Yes. For a steel foundry, I’d generally avoid putting the wireless electronics directly in the hottest zone. The better architecture is a high-temperature thermocouple probe + wireless transmitter located in a cooler area, with the probe connected by a heat-rated cable.

A few options worth evaluating:

** | Probe measurement up to 1,250°C / 2,282°F | Bluetooth | Very high-temperature measurements where the electronics can be kept away from the heat | | **

** | Up to 800°C / 1,472°F | LoRaWAN | Long-range plant-wide monitoring | | Monnit ALTA Wireless Thermocouple | Fixed probe transmitter up to 400°C / 752°F; K-type configurations can support higher probe temperatures | Proprietary wireless | Industrial monitoring and alarms | | Omega UW Series Wireless Thermocouple | Depending on thermocouple type, up to 1,760°C / 3,200°F (R/S); K up to 1,260°C / 2,300°F | Wireless receiver system | Heavy industrial/process applications | | NCD Wireless Thermocouple | Electronics rated to 260°C / 500°F; K-type probe | 2.4-GHz wireless | Lower-cost industrial monitoring |

The Omega UW Series is particularly interesting for foundry work because it supports multiple thermocouple types, including K, R, S, B, and N, with R/S thermocouples rated to about 1,760°C. Its wireless transmitter is separate from the thermocouple sensing element.

• Phantom EPH-T25 Wireless Thermocouple Module - $259.95 (Erbessd Instruments)

What I'd choose for a steel foundry

If you're measuring molten steel, furnace interiors, ladles, or very hot refractory surfaces, I'd look first at a Type K, N, R, or S thermocouple with a remote wireless transmitter, rather than a conventional wireless temperature sensor.

For example:

• Up to ~1,000–1,200°C: Type K or N can be appropriate.
• ~1,200–1,600°C: R or S is generally more appropriate.
• Molten steel temperatures (~1,500–1,700°C): look at R/S/B thermocouples and appropriate refractory/ceramic protection, rather than relying on the transmitter's advertised temperature range.
• Ambient around the transmitter >100–150°C: this becomes a separate engineering problem; you'll likely need a remote transmitter, heat shield, thermal standoff, or water-cooled/air-cooled mounting.

One important distinction: a product advertised as measuring 1,250°C does not mean its wireless electronics can sit in a 1,250°C environment. For example, Monnit's system can measure high temperatures through the thermocouple while the transmitter itself needs to remain within its specified ambient operating limits.

If you tell me where in the foundry you're measuring (furnace, ladle, casting line, conveyor, mold, refractory, etc.) and the approximate ambient temperature at the sensor location, I can narrow this down to 3–5 specific industrial sensors and compare temperature rating, wireless range, battery life, enclosure/IP rating, and hazardous-area certification.

Yes. For a steel foundry, the key distinction is the temperature of the sensing point versus the temperature the wireless electronics can actually survive. Many products advertise 500–2,000°F measurement capability, but the radio/battery enclosure must usually remain much cooler.

Strong candidates

• Phantom EPH-T25 Wireless Thermocouple Module - $259.95 (Erbessd Instruments)

• Linovision LoRaWAN Industrial Temperature Sensor - $189.00 (Hinovision Solutions LLC (Linovision USA))

• Monnit ALTA Industrial Wireless High Temperature Sensor - $196.22 (Absolute Automation USA)

• NCD 3-channel Industrial Wireless Thermocouple — probably the most interesting architecture for a foundry. The electronics enclosure is rated only to 85°C/185°F, but the thermocouple probe can be upgraded to 1,090°C/2,000°F. It supports K-type and other thermocouple types and long-range wireless mesh.

• Monnit ALTA Industrial High-Temperature — wireless RTD measurement from −50°C to 370°C (−58°F to 700°F). It's explicitly intended for furnaces, ovens, heaters and boilers.

• Theta Sensors ST103-L / ST100-KL — LoRa wireless sensors with thermocouple options. The ST103-L is specified to 600°C/1,112°F, while the external-probe ST100-KL goes as high as 1,350°C/2,462°F.

• NCD Long-Range Wireless Thermocouple — standard probe to 260°C/500°F, but the transmitter can accept higher-temperature K-type probes.

• Phase IV / Leap Sensors high-temperature wireless RTD — the RTD itself is rated to 500°C/932°F, while the electronics are rated to 120°C and the housing can survive specific short-duration exposures up to 250°C/482°F. This is more suitable for transient furnace exposure than continuous foundry ambient temperatures.

What I'd use in a steel foundry

If you're measuring molten metal, ladles, furnace walls, molds, or refractory, I'd favor a remote thermocouple with the wireless transmitter mounted well away from the heat. For example:

High-temperature probe → mineral-insulated/armored thermocouple cable → wireless transmitter in a cooled/shielded location.

That approach is substantially more robust than putting a battery-powered wireless node directly beside a furnace.

For continuous temperatures above ~500°F, I'd especially investigate the NCD/Theta thermocouple configurations rather than an integrated wireless RTD. The NCD system, for example, separates the 2,000°F-rated probe from electronics limited to 185°F.

Also, if the foundry has flammable gas/dust or classified hazardous areas, certification matters as much as temperature rating. Yokogawa's XS550/XS110A, for example, is designed for hazardous-location installations including steel plants, although its wireless module's ambient operating limit is only 85°C/185°F.

If you tell me the maximum temperature at the sensor location (e.g. 400°F, 800°F, 1,500°F, 2,500°F), what you're measuring, and whether the sensor itself must sit in the hot zone, I can narrow this to 3–5 specific industrial models and compare temperature rating, wireless range, battery life, hazardous-area certification, and approximate price.

In a steel foundry, deploying wireless sensors requires a clear division between the sensing element (which can endure extreme heat, like molten metal or furnace interiors up to +1000°C or more) and the wireless transmitter/housing (which must be thermally isolated, remote-mounted, or shielded because internal electronics generally fail above +125°C).

Industrial wireless sensors engineered to survive these heavy-duty environments rely on rugged enclosures (such as 316L stainless steel or heavy-duty cast housings), welded seams, specialized Lithium-thionyl chloride (Li-SOCl₂) batteries rated for wide thermal windows, and robust communication protocols like WirelessHART or LoRaWAN to punch through electromagnetic interference (EMI) from electric arc furnaces (EAF).

Top choices and configurations rated for extreme heat and foundry conditions include:

Industry standard for heavy heavy-industries. The transmitter housing is remote-mounted or thermally isolated away from the intense radiant heat point, paired with high-temperature thermocouples (Type B, S, or K) that can measure extreme process temperatures. It utilizes the secure WirelessHART protocol, designed to resist harsh plant EMI.

Features an external RTD probe tethered by a high-temperature lead wire, allowing the probe itself to handle extreme environments (up to +370°C for standard high-temp variants) while the robust NEMA 4X / IP65-rated Monnit Industrial-Grade Wireless High Temperature Sensor Go to product viewer dialog for this item. housing sits safely outside the direct radiant zone.

Built with vibration-resistant construction and IP67 waterproof/dustproof enclosures. When paired with armored high-temperature probes, they can span extreme fluid or surface ranges (-200°C up to +800°C) using high-capacity Li-SOCl₂ internal batteries designed for multi-year industrial lifespans.

For mechanical load/weight monitoring near molten metal, these systems incorporate specialized thermal fabric jackets and steel plate heat shields to deflect extreme radiant heat away from the load cell and wireless transmission node.

To help narrow down the exact setup you need, could you share:

• Where precisely you are placing the sensor (e.g., direct furnace wall, near the EAF, ladle monitoring, or ambient roof)?
• What peak temperature and measurement type (surface, ambient, or immersion) you are targeting?

In a steel foundry, deploying wireless sensors requires separating the sensing tip/probe (which may directly contact extreme heat up to 1090°C or 2000°F) from the wireless radio/transceiver housing (which typically must remain in ambient zones below 85°C to 125°C unless specially shielded).

Industrial solutions rely on a remote probe architecture linked via high-temperature cabling or thermal barriers. Leading options and configurations for extreme foundry heat include:

• NCD Industrial Wireless Thermocouple Sensors Go to product viewer dialog for this item.: These long-range wireless transmitters feature a K-type thermocouple connector that pairs with heavy-duty probes (such as shielded ceramic or high-grade metal-sheathed probes from suppliers like Omega). While the radio transmitter box is IP65/NEMA-rated and kept at a safe distance, the attached K-type thermocouple probe can continuously measure extreme process temperatures up to 980°C (1800°F) or 1090°C (2000°F) short-term.
• Monnit ALTA Industrial Wireless High-Temperature Sensors Go to product viewer dialog for this item.: Utilizing a glass-coated platinum RTD probe, this system accurately measures process temperatures from -50°C to +370°C (-58°F to +700°F). The industrial-grade weather-proof enclosure (IP65/NEMA 4X) houses the radio and is connected via high-temperature lead wires (available in lengths up to 100 feet), allowing you to keep the battery and transmitter away from direct radiant heat.
• Phase IV Engineering Industrial Wireless High-Temperature RTD Systems Go to product viewer dialog for this item.: Designed for harsh manufacturing and oven/furnace-adjacent tracking, these units support multi-channel 3-wire RTD configurations. The electronics node handles ambient temperatures up to 125°C (257°F) and can tolerate passing through or sitting near intense heat zones when paired with specialized thermal barriers and custom-length probe cabling.
• Specialized Heat-Shielded Enclosures / Accessories: For non-temperature applications (like load monitoring or vibration on machinery near molten metal paths), companies like Eilon Engineering provide specific thermal fabric jackets and steel plate heat shields that bolt directly onto industrial wireless hardware (such as crane scales or structural sensors) to deflect severe radiant heat.

Key Design Considerations for Foundries

• Probe vs. Housing Separation: Never mount the actual radio transceiver or lithium battery pack directly onto hot surfaces. Use remote-leaded thermocouples or RTDs with long silicone- or armor-wrapped cables.
• Battery Chemistry: Ensure the wireless nodes use Lithium-Thionyl Chloride (Li-SOCl₂) primary cells, which maintain stable self-discharge rates and operational capacity in high ambient-heat industrial spaces.
• EMI/RF Hardening: Electric arc furnaces (EAF) and heavy induction gear generate massive electromagnetic interference (EMI). Look for units with robust RF shielding and frequency-hopping spread spectrum (FHSS) protocols or WirelessHART mesh architectures to prevent packet loss.

If you can share what specific parameter you are measuring (e.g., molten metal temperature, surface vibration on a casting machine, or ambient roof gas temp) and the approximate ambient temperature where the radio transmitter would sit, I can narrow down the exact protocol and mounting setup you'll need.

Yes—but for a steel foundry, the key distinction is the temperature rating of the sensing element/probe versus the temperature rating of the wireless electronics. You generally do not want the radio/battery sitting directly in a 500–1,000+ °C zone.

Strong candidates

LoRaWAN Wireless Industrial Temperature Sensor -200 to 800°C

$179.00

Phantom EPH-T25 Wireless Thermocouple Module

$259.95

Thermo Scientific Smart-Vue Pro High-Temperature Sensor

$1,102.00

The OMEGA UW transmitter is particularly interesting for a foundry because the wireless transmitter itself has an operating limit of only about 70°C, while the attached thermocouple can measure dramatically higher process temperatures. For example, Type B supports up to 1,820°C and Type C up to 2,315°C.

The NCD system similarly separates the wireless electronics from the high-temperature probe. Its optional probe is specified for roughly 980°C continuous and 1,090°C short-term, depending on thermocouple construction. However, NCD explicitly warns that exposing the battery-powered electronics to excessive heat can damage the batteries, so this needs thermal separation.

For a permanent installation, Milesight's EM500-PT100 T800 is another interesting option: its PT100 configurations go up to 800°C, with LoRaWAN wireless communication and threshold/change alarms.

What I'd choose for a steel foundry

• ~200–500°C: wireless RTD/PT100 or thermocouple sensor can work directly on equipment.
• 500–800°C: use a high-temperature probe with the wireless transmitter mounted in a cooler location.
• 800–1,200°C: I'd favor a Type K/N/R/S/B thermocouple + remote wireless transmitter, with ceramic/mineral-insulated and appropriate metal-alloy sheathing.
• Molten steel / furnace interior: don't put a conventional wireless sensor in the hot zone. Use a high-temperature thermocouple or specialized immersion/profiling assembly, with the wireless electronics outside the thermal barrier.

For comparison, Fluke's Datapaq system uses mineral-insulated Type K probes and thermal barriers for processes up to 1,050°C, illustrating the kind of thermal isolation needed for furnace applications.

Important: if this is actually a steel-melting operation, tell me the approximate temperature (e.g. 400°C, 800°C, 1,200°C, 1,600°C), whether you're measuring molten metal, furnace atmosphere, refractory/shell temperature, or equipment surface, and whether the area is hazardous/explosion-classified. I can then narrow this to 3–5 industrial-grade sensors that are genuinely appropriate rather than just sensors with a high measurement range.

In a steel foundry, deploying wireless sensors requires distinguishing between ambient electronics survival limits (the harsh surrounding air, which might hit 60°C to 85°C near furnaces or casting bays) and process tip/probe limits (the extreme contact or radiant heat reaching up to 1,090°C+ or 2,000°F). Standard radio enclosures fail quickly under direct radiant heat, heavy vibration, and electromagnetic interference (EMI) typical of electric arc furnaces.

To monitor these environments reliably, industrial setups use a split-architecture design : a robust wireless transmitter housed away from the direct heat zone, connected via heavy-duty high-temperature cabling to a specialized contact probe or thermocouple.

Top industrial wireless sensor systems engineered for these harsh conditions include:

Features a long-range wireless mesh transmitter (IP65-rated wall/magnet mount enclosure) coupled with a K-type thermocouple probe (like Inconel 600 overbraided or ceramic-beaded leads) capable of measuring extreme process temperatures up to 980°C (1,800°F) continuous and 1,090°C (2,000°F) short-term. They also offer Class 1 Division 2 (C1D2) certified variants for hazardous foundry areas.

Utilizes a glass-coated platinum RTD probe on a durable lead (available in lengths up to 100 feet). While the remote probe can measure extreme media/surface temperatures from -50°C up to +370°C (700°F), the NEMA 4X / IP65 industrial radio enclosure is safely remote-mounted where ambient temperatures remain within -40°C to 85°C.

Specifically designed for high-ambient thermal mapping, featuring specialized electronics nodes rated for higher ambient operational envelopes (up to 120°C / 248°F for the node and 250°C / 482°F for specific high-temp variants) using 3-wire RTD configurations for high accuracy and EMI immunity.

Built with vibration-resistant construction and IP67 waterproof housings. They support heavy-duty armored or threaded RTD probes capable of extreme process range tracking from -200°C up to 800°C (1,472°F).

To help narrow down the best setup for your specific application, could you tell me:

• What specific asset or process are you monitoring (e.g., ladle preheaters, electric arc furnace ducting, bearing temps, or ambient casting bay conditions)?
• What is the estimated ambient temperature where the wireless transmitter housing would need to be mounted?

Yes—but in a steel foundry, the key distinction is the temperature the sensing element can measure versus the temperature the wireless electronics/battery can actually survive. Most wireless electronics cannot sit directly in a 500–1,500°C process zone.

Good candidates

For example, Monnit's industrial wireless high-temperature sensor uses a glass-coated platinum RTD and is specified for −50 to 370°C.

Monnit ALTA Industrial Wireless High Temperature Sensor

$196.22

Swift's system puts the electronics in an IP66 enclosure while using a stainless-steel probe rated to 300°C.

For genuinely extreme foundry temperatures

If you're talking about molten steel, ladles, furnace interiors, or radiant temperatures above 500°C, I would not put a conventional battery-powered wireless transmitter in the hot zone. A better architecture is:

High-temperature thermocouple / infrared sensor → high-temperature cable or fiber → wireless transmitter located in a cooled/shielded area.

For example, industrial infrared pyrometers can measure targets up to 3,200°C, while the electronics are kept away from the heat; Fluke's fiber-optic version can tolerate ambient temperatures up to 315°C without cooling.

There are also specialized wireless thermocouple systems where the probe is separated from the transmitter. NCD's unit, for example, can accept a higher-temperature thermocouple even though its supplied probe is rated to 260°C.

For a steel foundry, I'd narrow the choice based on four numbers:

1. Maximum ambient air temperature at the sensor electronics
2. Maximum surface/process temperature you need to measure
3. Whether it's near molten metal / intense radiant heat
4. Required wireless range and whether the area is classified hazardous

If you tell me the approximate temperature—e.g. 300°C, 500°C, 800°C, or 1,500°C—and whether you're measuring molten steel, furnace walls, ladles, bearings, or ambient air, I can give you a much more specific shortlist.

Yes—but for a steel foundry, the key distinction is the temperature rating of the sensing probe versus the wireless transmitter. Most wireless electronics cannot survive anywhere near molten steel temperatures; the usual industrial design is a high-temperature thermocouple in the hot zone with the wireless transmitter mounted in a cooler location.

Strong candidates

NCD is particularly interesting because its wireless unit accepts an external Type-K thermocouple, so you can select a probe appropriate to the actual furnace temperature rather than putting the electronics in the hot zone. NCD specifies an optional Omega probe rated to 1,090°C.

Erbessd Phantom EPH-T25 Wireless Thermocouple Module

$259.95

The Phantom EPH-T25 is another attractive option if Bluetooth is appropriate for your installation; its listed capability is up to 1,250°C with a suitable Type-K thermocouple.

For molten steel, I'd use a different architecture

Steel melting temperatures are typically around 1,500–1,650°C (2,730–3,000°F), which exceeds the practical range of ordinary Type-K probes and far exceeds the survival temperature of wireless electronics.

For that environment, I'd look at:

• Type S or Type R thermocouples for sustained measurements above roughly 1,200°C.
• Ceramic/refractory protection tubes around the thermocouple where appropriate.
• Put the wireless transmitter outside the furnace's radiant/convective heat zone, connected to the thermocouple by a high-temperature cable.
• For truly extreme temperatures or difficult RF environments, investigate fiber-optic or passive/batteryless high-temperature sensing. Research-grade wireless/batteryless SAW sensors are specifically being developed for hostile high-temperature environments.

One important caveat: a sensor advertised as "1,250°C" doesn't necessarily mean it can sit continuously in a 1,250°C steel-furnace atmosphere. Probe sheath material, radiation, oxidation, immersion time, mechanical shock, slag, and thermal cycling can drastically affect service life.

If you tell me the actual temperature (e.g. 800°C, 1,200°C, 1,600°C), what you're measuring (furnace wall, molten steel, ladle, mold, bearing, etc.), and whether you need continuous wireless telemetry or occasional measurements, I can narrow this to 3–5 industrial-grade sensors that are actually appropriate for a steel foundry.

In a steel foundry environment, monitoring extreme heat presents a dual challenge: the process/media temperature (which can reach hundreds or thousands of degrees) and the ambient operating temperature around the electronics and batteries, which are vulnerable to radiant heat, electromagnetic interference (EMF), and heavy dust.

Industrial wireless systems solve this by utilizing remote-mount probes or thermocouples that handle extreme process heat, connected via extension wire or insulated leads to a rugged, weather-resistant wireless transmitter housed safely away from the peak radiant zone.

Top industrial wireless sensor solutions rated for these harsh environments include:

Utilizing secure WirelessHART mesh networks, these transmitters feature robust dual-compartment housings built for high-vibration and extreme industrial atmospheres. When paired with heavy-duty industrial RTDs or thermocouples, they provide high-accuracy surface or process monitoring while keeping the radio and power module in a rated safe ambient envelope.

These weather-resistant, battery-powered wireless thermocouple/RTD transmitters are encased in NEMA 4X (IP65) or rugged enclosures and can accept high-temperature specialized probes (like Type R, S, B, or C high-temp noble metal thermocouples capable of reading up to 1650°C to 2300°C / 3000°F+). The transmitter body itself is kept at acceptable ambient limits (typically up to 70°C / 158°F) via proper standoff or remote lead placement.

Featuring weather-proof, NEMA-rated industrial enclosures, these long-range wireless sensors support specialized high-temperature glass-coated RTD probes capable of measuring extreme surface or ambient process temperatures up to 370°C (700°F), while utilizing heavy-duty industrial batteries and robust casing designed for manufacturing floors.

Built with extreme environments in mind, these long-range wireless transmitters support heavy-duty K-type or noble-metal high-temperature probes (such as Omega XCIB high-temp assemblies) rated to handle extreme process applications up to 1090°C (2000°F) or higher, transmitting reliable packet data over long distances past heavy foundry infrastructure.

To help narrow down the exact configuration you need, please let me know:

• What is the approximate process temperature and the ambient temperature where the transmitter housing will be mounted?
• Are you measuring surface temperature, ambient air , or immersed/molten material?

I can provide a more tailored hardware and network recommendation.