Mercury Vapour Generators are used to produce a known concentration of mercury for a range of applications including;

• Calibration of Mercury Monitors and Mercury Analysers

• System integrity test

• Sampling system testing for losses/drift

• Spike testing Mercury Monitors and Mercury Analyser Systems

• Spiking process for Catalyst removal efficiency testing

The P S Analytical 10.534 and 10.536 series of calibration gas generators can accommodate all these applications and have the capability of being extended to cover any applications which may be required in the future. They are available with the following options;

• Control Mode - Manual or Comput

• er Control

• Reservoir Type - Hg Bed or Permeation Device

• Flow and Temperature Limits - Flow rate and oven temperature variations

Method of Control

The PSA 10.534 series of calibration gas generators are manually controlled, whilst the PSA 10.536 series offers full computer control via MODBUS RTU connection.

With the PSA 10.534 series the PSA CavkitCalc software is used to calculate the flow rate and temperature settings required to generate the desired mercury concentration. The temperature and flow rates are then selected using the controls on the front of the instrument.

The PSA 10.536 series is computer controlled (via MODBUS RTU) using the PSA CavkitCalc Software or the PSA Online Software. The software packages are used to calculate the settings required to generate the desired mercury concentration and to automatically implement the settings. With the PSA Online Software, the concentration can be automatically varied for different tests or multipoint calibrations and the gas flow can be stoppen when not required.

The PSA 10.536 series mercury generators are typically used within complete PSA Mercury CEM's where the automatic features allow a wide array of tests to be performed with minimal user intervention.

The PSA 10.534 series mercury generators are typically used in more manual systems where standalone operation and direct control is required.

Reservoir Type

For the majority of applications, e.g. continuous emissions monitors for stack gas and removal technology testing, the levels required are in the microgram per cubic metre (µg m^-3) range supported by either the standard (no part number suffix) or High-Level (part number suffixed "h") Mercury Vapour Generators featuring a mercury reservoir are used.

For low level applications such as air monitoring where nanogram per cubic metre cubed (ng m^-3) concentrations are required, the Low-Level Mercury Vapour Generators (part number suffixed "L") featuring mercury permeation tubes are employed.

The standard and high-level options include a mercury reservoir. These units operate on the principle of dilution a saturated source of mercury at a known temperature. A low flow rate is passed across the mercury reservoir ensuring that the gas becomes saturated with mercury. The mercury-saturated gas is then diluted into the concentration range of interest. The flow rates are controlled using two mass flow controllers. The unit also generates a Hg free zero span so that the blank measurements can be performed. The Hg concentration can be adjusted by altering the temperature of the oven or by adjusting the reservoir or dilution flows.

The low-level options include a permeation tube in place of the mercury reservoir. With this option, the permeation rate is first established at the temperature of interest and the concentration then changed by adjusting of the dilution flow rate. Different concentration ranges can also be achieved by use of permeation tubes with different permeation rates.

Flow Rates/Temperature Ranges

The last option is the flow rate range of the mass flow controllers (MFCs) and the available range of the oven temperature.

The standard and low-level options feature 0-20 ml min ^-1 reservoir/permeation flow rate range and a reservoir/permeation tube temperature range of 30-60^oC to permit good control over the lower flow rate ranges.

The high-level options feature hotter ovens to generate higher saturated mercury concentrations from the oven and a 0-30 ml min^-1 reservoir flow rate to further increase the maximum mercury flow available.

Table of Models:

Model

10.534/10.536

10.534L/10.536L

10.534H/10.536H

MFC 1

MFC 2

Oven

Hg Source

Concentration Range

0-20 ml min^-1

0-20 l min^-1

35 - 60ºC

Reservoir

1.7 - 3000 µg m³

0-20 ml min^-1

0-20 l min^-1

0-60ºC

Permeation Tube 0.06 ng min^-1

3 - 60 ng m^-3

0 - 30 ml min^-1

0 - 20 l min^-1

35 - 100ºC

Reservoir

13 µg m^-3 - 13 mg m^-3*

* 13 mg m^-3 calibration gas is saturated at room temperature, with appropriate heat tracing higher temperatures are possible.

IMPORTANT NOTE: For applications where Mercury concentrations higher than 13mg m ^-3 are required P S Analytical has the C536H100 and C536H200 along with the R variant of the 10.534/10.536.

These modules are designed to work at even higher temperatures and flows in order to generate more Hg vapour. The R variant of the 10.534/10.536 has control valves filtered which allow the reservoir and dilution gases to be diverted from the normal oven to the C536H100/C536H200 extended oven. This oven can reach 200^oC and can also be located close to the process, thus minimising heated lines.

To discuss any particular requirements and/or for more detailed information on the above products please complete the Information Request Form.

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