The WIKA CTI5000 is a portable infrared calibrator covering 50 to 500°C with a 57 mm diameter target plate. It is designed for one job: verifying infrared thermometers and thermal imagers in the field without dragging a blackbody furnace to the measurement point. This article covers how to operate it, what the specifications mean in practice, and answers to the questions WIKA field service hears most often.
Unlike a dry block calibrator — which requires physical contact between the sensor and the metal block — the CTI5000 generates a temperature-controlled flat-plate target with a known surface emissivity. You aim the infrared thermometer at the target, compare the reading to the CTI5000's reference value, and calculate the deviation. The key is understanding that it calibrates the radiometric path: emissivity setting, field of view, and detector response — not just the thermometer's electronics in isolation.
Operating the CTI5000: Key Controls and Readings
- Temperature range
- 50 to 500°C (122 to 932°F), setpoint adjustable in 0.1°C increments. The target plate reaches setpoint from ambient in approximately 15 minutes for 500°C.
- Target diameter
- 57 mm — this is the critical physical constraint. The infrared thermometer under test must have a field of view that fits entirely within the 57 mm target at the measurement distance. A thermometer with a 12:1 distance-to-spot ratio must be placed no farther than 684 mm from the target to avoid reading outside the controlled area.
- Emissivity setting
- The CTI5000 target plate has a calibrated emissivity of 0.95. Set the IR thermometer under test to ε = 0.95 before comparing readings. If the thermometer's emissivity is fixed at 0.95, no adjustment is needed.
- Stability indicator
- The display shows a stability marker when the target temperature is within ±0.2°C of setpoint. Wait for this indicator before recording a comparison reading — the target plate temperature lags the setpoint during heat-up and cool-down.
- Reference accuracy
- ±0.5°C across the full range, with a display resolution of 0.1°C (0.1°F selectable).
What is the minimum thermometer spot size the CTI5000 can calibrate?
The 57 mm target plate is the limiting factor. Any IR thermometer whose measurement spot is smaller than 57 mm in diameter at the chosen distance can be calibrated — but you need to calculate the distance-to-spot (D:S) ratio carefully. For example, an IR thermometer with a 50:1 D:S ratio has a spot diameter of 20 mm at 1 meter — well within the target area. But at 3 meters, the same thermometer's spot is 60 mm, which exceeds the 57 mm target, and the reading will include cooler background. For thermometers with very wide fields of view (low D:S ratios under 8:1), place the thermometer as close to the target as the instrument's minimum focus distance allows to keep the spot within the target plate.
When should I use the CTI5000 instead of a dry block calibrator?
Use the CTI5000 when calibrating non-contact infrared thermometers, thermal imagers, or any radiometric sensor where the measurement principle requires a surface with known emissivity. A dry block — such as the WIKA CTD9100-375 — calibrates contact probes (RTDs, thermocouples) by inserting them into a metal well at a controlled temperature. The two instruments complement each other: a dry block calibrates the contact reference thermometer, and the CTI5000 calibrates the IR thermometer that cannot be inserted into a well. Some facilities run the CTI5000 at 100°C and verify it against a contact probe measured in a dry block to cross-validate both instruments.
Does the CTI5000 need emissivity correction for different target surface finishes?
No — and this is important to understand. The CTI5000 target plate has a fixed surface with ε ≈ 0.95. You are calibrating the IR thermometer against this known target, so the IR thermometer's emissivity setting should match the target: set it to 0.95. The purpose of the calibration is to verify that the thermometer reads correctly when its emissivity setting matches the target surface. If you later use that thermometer to measure a shiny metal surface at ε = 0.3, you would adjust the thermometer's emissivity to 0.3 for that measurement — and the calibration at 0.95 gives you confidence that the detector and signal processing chain are working correctly at the reference condition.
How long does the CTI5000 run on battery power?
The CTI5000 is mains-powered (100–240 VAC, 50/60 Hz) and does not include an internal battery. For field use where AC power is unavailable, WIKA recommends powering it through a portable inverter connected to a vehicle or generator. The power consumption is approximately 200 W during heat-up and 100 W at steady state. If field battery operation is a hard requirement, the CTI5000's form factor is the tradeoff — the 57 mm target plate and ±0.5°C reference accuracy require more heating power than a battery-powered handheld can deliver.
Comparing the CTI5000 to Other WIKA Temperature Calibrators
WIKA builds a full range of temperature calibration instruments. Where the CTI5000 fits depends on your workload:
| Model | Type | Best For |
|---|---|---|
| CTI5000 | IR target plate | Field calibration of IR thermometers and thermal cameras |
| CTM9100-150 | Multifunction | Four-in-one: dry block, IR target, surface sensor, and liquid bath simulation |
| CTD9100-375 | Dry block | Fast-heating contact probe calibration up to 375°C |
| CTD9100-165 | Dry block (Peltier) | Below-ambient calibration from -35°C, no external chiller needed |
| Mensor CTD9350 | Dry block | Wide-range contact calibration, -35 to 700°C, with 0.001°C resolution for precision lab use |
If your calibration workload is dominated by handheld IR thermometers used for preventive maintenance — checking motor bearings, steam traps, electrical panels — the CTI5000 is the right instrument. If you also need to calibrate RTDs and thermocouples, the CTM9100-150 gives you both IR target and dry block capability in one unit, at a higher price point. Browse our full temperature calibrator catalog for dry block, liquid bath, and IR target options, or see our dry block calibrator lineup if your workload is primarily contact probes.
