Metal Halide Electronic Ballasts

Metal Halide lamps are rugged, powerful, emit white light, and last 20X longer than incandescents. They have the highest CRI of any lamp and provide for excellent color rendering. Paired with a MERCRON lamp controller, the lamps are as steady as sunshine!

Click on respective tabs of interest…


The Metal Halide light-source is a (H.I.D.) high-intensity, discharge lamp, made desirable for Machine Vision applications by MERCRON since it is –

  • Especially useful in compact installations;
  • A very good source of white light;
  • Extra versatile due to a variety of many package-sizes;
  • Available in a range of controllable intensity-levels: 250W– 1000W.
  • Emits continuous, ripple-free light when precisely regulated by MERCRON

Nonetheless, some are unsuitable:

  • HMI
  • HQI *
  • HTI

* Notable Exception: The Osram HQI 400 with a Color Rendering Index (CRI) of 93.


Rule of thumb: The shorter the arc, the greater the ignition-voltage necessary.

Any MH lamp requiring ignition-voltage greater than 5000 V should not be used in Machine Vision applications.

MERCRON-regulated METAL HALIDE Lamps: Before & AFTER
Any light-sources has its pros and cons.
The most appropriate lamp is determined by several factors:
  • color of target
  • background color
  • color sensitivity of both the detector and the camera
  • color temperature of the lamp itself
Regardless, MERCRON allows the System Designer to capitalize upon its positives, and goes a long way to eliminate its negatives.
Strong Points

  • Rugged and powerful
  • Emits white light
  • Available in many sizes
  • Useful in compact installations
Potential Drawbacks

  • Color rendition not the best
  • Colors spatially distributed
  • Sensitive to operating level
  • Diffusers should be used
  • Arc stability can be compromised by positioning

But when regulated at high-frequency by MERCRON…

  • Flicker-free, steady light
  • Regulated spectral stability

Metal Halide Light Controllers

MERCRON makes several models for each lamp type.

Before ordering, please contact MERCRON to determine the most appropriate model for your application.

Y-models - which include onboard power factor correctors - are generally required when multiple lamp ballasts (Light Controllers) are used in a single installation, and/or for operation in Europe. Their model number’s prefix will be HY.

When ordering, be sure to specify correct version: 120 VAC or 230 VAC. MERCRON will confirm the prefix of the correct model number.

Model Can
Lamp Type Wattage
Light Dimming
HX250 1 M250 or R2502 250 2:1
S250H 1 M250 or R250 250 3:1
HX400 1 M400 or R400 400 2:1
S400 1 HQI4003
400 3:1

1Possibly others; we will test your lamp(s) for FREE.
2M250 = Metal Halide Lamp of 250 watts; R250 = Mercury Lamp of 250 watts.
3HQI lamp is technically classified as a MH (Metal Halide) lamp; however, it has the voltage and current rating of a Sodium lamp. Therefore, it is listed here with other MH lamps, but requires a Sodium Light Controller; hence, its model number is different.

METAL HALIDE Light-Controllers' Dimensions

Regular Metal Box:
9.5" X 5.125" X 2.625"
(241 X 130 X 67 mm)
Long Metal Box:
11" X 5.125" X 2.625"
(279 X 130 X 67 mm)
4 - 5 lbs
(1.8 - 2.3 kg)
3" X 8-32 or 10-32 bolts

Mechanical Specifications

Some of our customers over the past 30 years: