Optimising Kiln Temperature with Keller PK-11 Series
Kiln temperature is simply the temperature inside the kiln along its length and over time. When that kiln temperature drifts or swings around, product quality, fuel bills and even refractory life all take a hit.
Across cement, lime, brick, tile and ceramics plants in NSW, VIC, QLD, WA and other states, stable kiln temperature control is now a major lever for cost and quality. This guide explains how infrared pyrometers measure kiln temperature, why the Keller PK-11 Series fits industrial kilns, and how CISCAL supports supply, setup and NATA-accredited calibration.
Common Kiln Temperature Problems
Many sites across Australia see the same kiln temperature issues:
Uneven temperature zones – One side of the tunnel kiln is hotter, or the burning zone in a rotary kiln is narrow and unstable.
Hot spots and cold spots – Refractory hot spots on a rotary shell, or cold channels through a load of bricks or tiles.
Relying only on thermocouples – A few fixed thermocouples can miss what is happening on the product surface or in the load, especially in long tunnel kilns.
Impact on scrap, rework and downtime – When kiln temperature is not monitored properly, scrap rates rise, more product needs refiring and unplanned shutdowns become more common.
Infrared pyrometers give a direct view of the actual surface temperature of product or refractory, filling in the gaps between thermocouples.
How Infrared Pyrometers Measure Kiln Temperature
Non-contact temperature basics
An infrared pyrometer is an infrared thermometer that measures temperature from the thermal radiation a surface emits, without touching it.
In simple terms:
Every hot surface gives off infrared radiation.
The pyrometer’s lens focuses that radiation on a detector.
Electronics convert the signal into a kiln temperature reading.
Because no probe or thermocouple is in the hot zone, non-contact kiln temperature measurement:
Works where access is limited or the load is moving
Avoids wear on probes in abrasive or high-velocity gas streams
Responds very quickly to changes in kiln temperature
Typical Kiln Applications
Infrared pyrometers are used on many kiln types:
Tunnel kiln temperature – Measure load or refractory temperatures at pre-heat, firing and cooling zones.
Rotary kiln temperature – Monitor clinker, lime or refractory temperatures through kiln viewing ports.
Shuttle / batch kilns – Check soak temperature at set points in the chamber.
Common mounting points include:
Firing zone ports on rotary cement kilns and lime kilns
Side or roof ports in tunnel kilns above the main firing and soak zones
Observation ports in cooling zones to control cooling rate
Introducing the Keller PK-11 Series for Kilns
The Keller CellaTemp PK 11 BF 2 is a compact infrared pyrometer well suited to kiln temperature monitoring in harsh industrial environments. It combines non-contact measurement with simple setup and integration into PLC or SCADA systems.
Core Features of CellaTemp PK 11 BF 2
Key features relevant to tunnel kiln temperature, rotary kiln temperature and batch kilns include:
Measuring range: 0–1000 °C (ideal for ceramics, cement kiln temperature and lime kiln temperature on product or refractory)
Spectral range: 8–14 μm, optimised for non-metal surfaces
Fast response: t90 ≤ 60 ms, so control loops see changes quickly
Stainless steel body with IP65 protection, suitable for dusty kiln areas
Analogue 0/4–20 mA output + IO-Link, for easy connection to PLCs and SCADA
Clear LED display and keypad on the sensor, so parameters can be adjusted onsite
These features allow maintenance and process teams in NSW, VIC, QLD, WA and other regions to mount PK 11 units close to the kiln, wire them into existing IO and read kiln temperature locally at the same time.
Smart Functions for Process Stability
Beyond basic temperature output, the CellaTemp PK 11 includes smart functions that support stable kiln temperature control:
Two PNP switching outputs – Can be set as alarms or limits, for example over-temperature on a tunnel kiln roof or low temperature in a pre-heat zone.
Emissivity and transmission factor adjustment – Lets you tune readings for different products (e.g. dark bricks vs lighter tiles) and any protective window between the pyrometer and kiln.
“Vitality” indicators and diagnostics – The vitality function monitors internal status and can flag when the device may need maintenance or checking, helping with preventive maintenance.
Choosing Between Keller PK 11-K001, K002, K003 and K004
The PK-11 measuring systems combine the PK 11 BF 2 sensor with different optics and mounting hardware. All have a 0–1000 °C measuring range and 8–14 μm spectral range.
Quick Comparison Table
Model | Measuring range | Target size | Focus distance | Mounting set | Key feature |
PK 11-K001 | 0–1000 °C | 11 mm | 0.3 m | PK 01-027 + cable VK 02/L AF 1 | Small spot for close-range kiln ports |
PK 11-K002 | 0–1000 °C | 33 mm | 0.9 m | PK 01-007 + cable VK 02/L AF 1 | Standard spot for longer viewing ports |
PK 11-K003 | 0–1000 °C | 33 mm | 0.9 m | PK 01-024 + cable VK 02/L AF 1 | Bayonet lock for quick removal |
PK 11-K004 | 0–1000 °C | 33 mm | 0.9 m | PK 11-006 + cable VK 02/L AF 1 | Bayonet lock + kiln-suited mounting combination |
Each mounting set includes an air-purged fitting with flow-optimised air to keep the lens clear with minimal air consumption.
Matching PK-11 Variants to Kiln Layouts
Close-range ports or pilot kilns → PK 11-K001 Good where the pyrometer can be mounted close to the product, such as small shuttle kilns, pilot kilns or inspection doors with limited space.
Standard tunnel or rotary kiln viewing ports → PK 11-K002 Suits many cement kiln and lime kiln applications where there is a longer standoff distance and a standard port size.
Dusty, high-maintenance points → PK 11-K003 or PK 11-K004 The bayonet lock makes it easy to remove the measure head for cleaning protective windows or lenses without disturbing brackets. PK 11-K004 adds a kiln-optimised mounting combination for heavy-duty use.
Practical Tips for Reliable Kiln Temperature Readings
Spot Size, Distance and Aiming
For accurate kiln temperature monitoring:
Make sure the measuring spot is fully filled by product or refractory; do not let the spot “see” frame edges or steelwork.
Select PK 11 optics so that spot size suits the kiln window or product size (e.g. 11 mm at 0.3 m vs 33 mm at 0.9 m).
Align the pyrometer so it looks at a stable part of the load, not just at holes or conveyors.
Dealing With Dust, Scale and Flames
In cement and lime kilns, dust and scale are a daily reality:
Use air-purged mounts supplied with PK 11 measuring systems to keep dust off the lens.
Where possible, avoid looking directly at flames; aim at the product bed or refractory opposite the burner.
Use bayonet-lock mounts (K003, K004) to remove the sensor quickly, clean protective windows and refit without re-aiming.
Integrating Keller PK-11 With Your Control System
The Keller PK 11 Series is designed for easy integration:
0/4–20 mA analogue output can feed directly into PID loops in your PLC or standalone controllers for kiln temperature control.
IO-Link supports parameter changes, diagnostics and remote monitoring from control rooms or SCADA.
Switching outputs can be used for over-temperature alarms, burner interlocks or cooling air control.
Steps to set up a Keller PK-11 on a kiln inspection port
Confirm the required measuring point (e.g. firing zone roof port on a tunnel kiln).
Choose the PK 11-Kxxx system that matches distance and port size.
Install the mounting set on the port, including air purge and any protective window.
Screw in the PK 11 BF 2 sensor and roughly aim at the target area.
Wire the 0/4–20 mA output to the chosen PLC or controller channel and connect IO-Link if used.
Set emissivity and measuring range via the keypad or IO-Link.
Check readings against existing thermocouples or reference data and fine-tune aiming as needed.
Calibration and Compliance for Kiln Temperature in Australia
Why calibration of kiln pyrometers matters?
Infrared pyrometers used for kiln temperature control sit inside quality systems and energy audits. Uncalibrated instruments can give biased readings which:
Lead to incorrect firing curves
Reduce confidence during customer or regulatory audits
Affect energy and emission reporting
In Australia, calibration traceability links back to NMI standards and is typically provided through ISO/IEC 17025 NATA-accredited laboratories.
How CISCAL supports Keller PK-11 users
CISCAL has held ISO/IEC 17025 accreditation with NATA (Accreditation No. 411) since 1963, with a scope that includes temperature meters, thermocouples, digital thermometers and temperature enclosures such as ovens and furnaces.
Support for kiln operators across Australia (NSW, VIC, QLD and other states) includes:
NATA-accredited calibration of temperature instruments in the lab and onsite, supporting traceable kiln temperature measurement.
Documentation for audits and OEM requirements, aligned with ISO/IEC 17025 and Australian measurement system expectations.
Assistance with setup, function checks and maintenance plans for Keller PK 11 pyrometers, including advice on mounting, emissivity and control loop integration.
Getting the Most Value from Your CISCAL services
Stable kiln temperature is one of the strongest levers for quality, throughput and energy efficiency in cement, lime, brick, tile and ceramics plants across Australia. The Keller PK-11 Series provides reliable, non-contact kiln temperature monitoring with fast response, IO-Link connectivity and smart diagnostics, while the different PK 11-K001 to K004 systems handle a wide range of kiln layouts.
CISCAL ties this hardware into a complete solution by supplying Keller PK-11 pyrometers, supporting correct installation and integration, and providing NATA-accredited, ISO/IEC 17025-compliant calibration for ongoing confidence in every kiln temperature reading.