Magnetic Particle Inspection (MPI) Equipment


Magnetic Particle Inspection Yoke

Heavy Duty NDT Yoke

The Johnson & Allen Yoke (JAY) has been a core product in our MPI equipment range for over two decades. Manufactured in-house the JAY has a proven track record for usability, durability and reliability. The core is encapsulated in a hard-wearing, impact and abrasion resistant polymer which makes the JAY one of the most heavy duty yokes on the NDT market. Like other Johnson & Allen yokes the JAY is fitted with a self-resetting thermal cut-out to prevent burnouts from misuse.

The JAY is supplied lift tested with certificate of conformity and in a heavy duty canvas bag as standard.

Available in 230V and 110V versions.

Replacement parts also available - Including pairs of complete leg sections, pairs of just the feet sections, micro switches, switch covers and rubber membranes etc.

JAY 'PAL' Option

The JAY can be supplied fitted with a Permanently Attached Light (PAL) pod. This rugged inspection light is contained in a purpose cast and resin filled pod and is operated using a switch independent of the energising function. Using an ultra-bright white LED cluster the PAL illuminates the area between the poles to in excess of 500 Lux - The minimum required by many MPI standards. The lead can also be upgraded to an armoured cable for increased robustness.

The JAY 'PAL' is ideal for night shift work where light is limited, on-site work where use of other light sources may be impractical and enclosed or difficult inspections that require freer hands to perform efficiently.

JAY PAL (permanently attached light)

Product Data

Model JAY - 230V JAY - 110V
Input Supply
230VAC @ 1.9A 110VAC @ 3.7A
Voltage Regulation ±10% of nominal ±10% of nominal
Frequency 50 / 60 Hz 50 / 60 Hz
Waveform AC AC
Switch Position Trigger Mounted Trigger Mounted
Recommended Pole Spacing 150mm 150mm
Pole Spacing Range 50 to 210mm 50 to 210mm
Leg / Pole Contact Size 25 x 25mm 25 x 25mm
Duty Cycle 25% - Max. ON time 30 seconds 25% - Max. ON time 30 seconds
Lift Strength
(100 to 150mm spacing)
> 4.5 kg
(Equivalent to 44 N)
> 4.5 kg
(Equivalent to 44 N)
Magnetic Field* > 2.5 kA/m
@ 6 inch / 152mm spacing
> 2.5 kA/m
@ 6 inch / 152mm spacing
Dimensions (LWH) 230 x 60 x 180mm 230 x 60 x 180mm
Weight 3.25 kg 3.25 kg
Ingress Protection IP56 IP56
Mains Lead 4 Meters 4 Meters
Plug Type ‘C’ Form - 16A ‘C’ Form - 16A
Warranty 12 Months 12 Months
Conformity UKCA

Specification Compliance

(List is not exhaustive)

ISO 9934: 2016
ASTM E 1444-22a
ASTM E 709-21
ASTM E3024-22a
ISO 9934: 2016
ASTM E 1444-22a
ASTM E 709-21
ASTM E3024-22a
Powerbelt Compatibility No Yes


*Note: The tangential extraneous magnetic field will vary depending on whether the yoke is energized in free space (unloaded) or when in contact with a part (loaded). Material properties and pole spacing will also alter the magnetic field. For this reason operators should not rely on field measurements alone as a performance check and should verify the lifting strength of the yoke with a 4.5kg test weight and use a QQI shim or flux indicator strip for evaluation before undertaking inspection.

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