Haloes Caliper
Manual inhibition zone reader
About Haloes Caliper
The IUL Haloes Caliper is a digital inhibition zone reader designed for fast, accurate measurement of antimicrobial susceptibility testing (AST) and microbiological potency assay results.
Developed to reduce the variability associated with traditional manual measurement methods, the Haloes Caliper combines digital precision, reproducible results, and an intuitive workflow for routine microbiology laboratories.
Users simply rotate the Petri dish using the smooth-turning control wheel and measure inhibition zone diameters directly on the integrated digital display. Its parallax-free reading system helps improve measurement clarity and consistency, supporting reliable interpretation of antimicrobial inhibition zones.
Ideal for laboratories performing antimicrobial susceptibility testing, antibiotic potency testing, and inhibition zone measurement, the Haloes Caliper helps streamline plate reading while providing greater confidence in every result.
Key Benefits
0.1 mm resolution for precise measurements.
Parallax-free optical design for edge-to-edge accuracy.
Instant digital readout for quick result recording.
Includes a Ø 30 mm disk for routine accuracy checks.
Workflow
Place the Petri dish on the movable platform in the illuminated field
Align one side of the halo to calibration line and press ‘Reset’
Use the handle wheel to find the opposite side of the halo
Read the diameter on the digital display
Our Solution at Work
Product Insights
The Haloes Caliper maintains a perpendicular view of the agar plate across the entire inhibition zone, eliminating parallax errors for more accurate measurement. Precision optics and perpendicular illumination provide a sharp, magnified view of halo edges, even when zones are irregular or poorly defined.
Halo measurement is easier, more reliable, and more accurate thanks to a smooth handle wheel for effortless plate rotation, and an easy-to-read digital display.
A smooth side wheel moves the image across the screen while the plate remains stationary, improving measurement consistency and control, allowing true edge-to-edge measurement.
Technical Specifications
| Model | Haloes Caliper - Zone Reader |
| Cat. | 9000900 |
| Magnification Factor | 2.25x |
| Measuring range | 0–35 mm |
| Resolution | 0.1 mm |
| Lighting | LED |
| Screen diameter | 55 mm |
| Operator Interface | Digital count display and ‘Reset’ button |
| Compliances | Allows compliance with ISO 7218 |
| Dimensions (W×H×D) | 27.0 x 27.0 x 23.0 cm / 10.6 x 10.6 x 9.0 in |
| Weight | 3.0 kg / 6.6 lb |
Specifications subject to change without notice.
Accessories
Tutorial Videos
Downloads
Frequently Asked Questions
The Haloes Caliper provides digital inhibition zone measurements with a resolution of 0.1 mm, enabling laboratories to detect small differences in zone diameters and improve the accuracy of antimicrobial susceptibility testing (AST).
The Haloes Caliper features a perpendicular viewing system and a screen-lens design that eliminate parallax distortion. This ensures clear visualization and accurate measurement of inhibition zones across the entire Petri dish viewing area.
The Haloes Caliper includes a 30 mm verification disk for routine performance checks and measurement validation. Optional 10 mm and 20 mm verification disks are also available for additional accuracy verification and quality control procedures.
The Haloes Caliper is compatible with Petri dishes up to 100 mm in diameter and can accurately measure inhibition zones up to 35 mm, making it suitable for standard antimicrobial susceptibility testing workflows.
Yes. The Haloes Caliper allows users to measure multiple inhibition zones individually on a single Petri dish, enabling accurate recording and analysis of each antibiotic susceptibility result.
Yes. Optional 4-halo and 6-halo placement templates are available to guide antibiotic disc positioning and promote consistent test layouts, helping improve standardization and reproducibility in susceptibility testing.