Falco 2

Which Lamp You Need, and Why It Matters

This is the decision to get right, and it’s worth two minutes before you look at anything else.

Photoionisation works by knocking an electron off a molecule. If the lamp carries less energy than the compound’s ionisation energy, nothing happens and the instrument reads zero. Not a low reading. Zero.

So a 10.6 eV PID in a room full of formaldehyde reads clean, and the reading is worthless. The gas is there, but the lamp can’t see it.

The short version: choose 10.6 eV unless your target compound is beyond its reach. It monitors continuously, the lamp lasts years rather than months, and it costs far less to run. Choose 11.7 eV when the compound leaves you no option.

Over 700 Compounds From One Sensor

Most fixed gas detection is compound specific. You decide what you’re looking for, then buy a sensor for it.

Volatile organic compounds don’t work that way. A solvent store, tank farm or process line can release any of hundreds of compounds, and the mix changes with what’s running that day.

The 10.6 eV lamp responds to anything that ionises at or below 10.6 electron volts. That covers the aromatics, hydrocarbons, ketones and alcohols that make up most industrial solvent exposure. Calibrated to isobutylene, one instrument gives a total VOC reading across them all. Customisable response factors let the reading be set for a specific compound.

Service It With the Power On

This feature saves money over the life of the instrument, and it’s easy to skim past on a datasheet.

The Falco 2 has dual certification. The main housing is ExD, and the sensor is intrinsically safe and mounted externally. Calibration and sensor servicing can be done in the hazardous area with the power on.

On a live plant, that makes routine calibration far simpler, with less shutdown planning and coordination. Across a fleet of detectors at a refinery, it changes the annual cost of ownership, not just the convenience. On the 11.7 eV lamp, which needs weekly calibration, it matters even more. Permit requirements are set by each site, so check yours.

Built for Weather, Not a Cabinet

PID sensors have a reputation for drifting in humidity. Condensation forms inside the sensor and the reading wanders.

Two ION Science technologies handle this. Typhoon Technology prevents condensation forming inside the PID sensor. Patented Fence Electrode Technology, with an anti contamination design, removes the effect of condensation on the response, so the instrument clears down properly instead of holding a false high reading.

The housing is rated IP65. In Australian terms, that means a Pilbara wet season, a coastal salt environment or a washdown area, without building a weatherproof cabinet around it.

Diffused or Pumped

The diffused model measures the air where it’s mounted. It’s simple, with no moving parts, and right when you know where the hazard will be.

The pumped model draws a sample through a line, covering pits, sumps, voids and confined spaces where mounting an instrument isn’t practical. Both share the same outputs and sensor technology. The 11.7 eV lamp comes in the diffused configuration only.

Understanding the Duty Cycle

An 11.7 eV lamp has a hard physical limit. Higher energy shortens lamp life, and on continuous operation, a high energy PID lamp lasts days rather than months.

ION Science’s answer is duty cycling. The lamp runs a fixed 60 second cycle, 20 seconds on and 40 seconds off, which stretches lamp life to about three months in service, or up to four months from delivery allowing for storage. The cycle is fixed and can’t be changed by the user.

A progress indicator shows where the unit is in its cycle, with an icon showing whether the lamp is on. That matters, because it tells an operator whether a zero reading means clean air or a lamp that happens to be off.

Maintenance on the 11.7 eV Lamp

Plan for this before you specify it, because a surprise six months in is worse than knowing up front.

ION Science recommends weekly calibration and weekly bump testing with a suitable span gas. Calibration is two point, thanks to the sensor’s linearity across the 0 to 200 ppm range. Lamps and filters can be replaced in the field. The lamp is warranted for three months from the date of sale, which reflects its working life rather than a defect window.

One practical point: the 11.7 eV lamp window must not be cleaned with the aluminium oxide polishing compound used on standard PID lamps, as it will damage the window. Only ION Science lamps fit the MiniPID 2 sensor, and anything else voids the warranty.

We can manage this under a scheduled service agreement and supply the span gas, which is the realistic way to keep a weekly cycle from slipping.

Integration

Outputs include 4-20 mA analogue, RS485 Modbus and two programmable relays. That covers a standalone install with local alarms, a connection to an existing fire and gas panel, or a site wide network reporting to a control room.

It runs on 8 to 40 VDC at typically 2 W, so it works on existing field power without a dedicated supply.

The interface is a high contrast OLED display with five tamper proof magnetic switches and LED confirmation, all operated without opening anything. A red, amber and green status display is visible from 20 metres in direct sunlight.

Where It’s Used

Refineries and petrochemical plants, tank farms and terminals, solvent and chemical stores, fenceline and fugitive emission monitoring, wastewater treatment works, contaminated land and remediation sites, lithium ion battery manufacturing and storage, pathology and mortuary formaldehyde monitoring, ethylene oxide sterilisation areas, methanol handling on gas processing plants, semiconductor and electronics cleaning, and marine terminals and cargo tank areas.