With a detection limit of 0.5µg / m3, the J405 is ideal for both industrial and residential cleanup settings.


Jerome® instruments have been recognized as the gold standard for mercury detection for 35 years.


Sturdy metal housing and solid-state design make the J405 tough enough for any environment.


With 24 hours of battery life per charge, the J405 is always ready when you need it.


Features on-board data logging for up to 20,000 measurements, USB data transfer, and SCADA interface capabilities through 4-20ma output.


Resolution: 0.01 µg/m3 (0.00001 mg/m3)
Detection Range: 0.5 µg/m3 – 999 µg/m3 (0.0005 mg/m3 to 0.999 mg/m3)
Data Storage Capacity: 20,000 samples
Operating Environment: 0 – 45°C non-condensing, non-explosive
Accuracy: 1.0 µg/m3, ±10%
25 µg/m3, ±5%
100 µg/m3, ±5%
Typical Response Time: SURVEY MODE: 2 seconds
SAMPLE MODE: 16 seconds
Flow Rate: 750 ± 50 cc/min (0.75 ± 0.05 liters/min)
Power Requirements: 12 VDC for the instrument

(provided by the internal battery, AC power supply/charger, external battery pack or car accessory cable)

100-240VAC, 47-63Hz, 3.2A for the AC power supply/charger

Internal Battery Pack: Rechargeable nickel metal hydride (NiMH)
Dimensions: 11″ L x 6″ W x 6.5″ H
Weight: 5.3 lbs.
Output: Digital: USB serial data to PC, printer or USB flash drive
Analog: 4-20mA current loop (requires external power source)
accurate to 0.3% of output
Warranty: 1 year, factory parts and labor


  • 1400 2002 Probe
  • 990-0193 Ammonia Filter
  • 990-0214 External Battery Pack Assembly
  • 990-0217 Jerome® Hard Carrying Case
  • 990-0220 Jerome® Soft Carrying Case
  • Y405-0903 Maintenance Kit
  • Y431 0902 Mercury Functional Test Kit w/Mercury
  • Y990-0191 Mercury Functional Test Kit w/o Mercury
  • Z2600 3940 Chlorine Filter


  • 2600 3039 Fritware
  • 600-0262 Scrubber Filter Assembly
  • 600-0293 AG Filter
  • Z2600 3905 Zero Air Filter


  • Meets EPA & ATSDR Action Levels
  • Battery Powered Sensor Regeneration
  • 24 Hour Battery Life
  • On-board Data Logging (20,000 data points) (communications option)
  • Auto Time/Date Stamp
  • USB data output (communications option)
  • SCADA Interface Capabilities via 4-20ma
  • Functional Test Kit (FTK) verifies instrument functions correctly between recommended annual factory calibrations