Document No LM0670 Issue A Rev 2 November 2017 Page 7 of 15
INTRINSIC SAFETY Exi – Installation notes
The reed-switch sensors do not require individual certification as they are classed as "simple apparatus".
No marking of the meter regarding intrinsic safety is required under the relevant code. Reed-switches are
covered under the Harmonised European Standards Clause 1.3 of EN50.014 and BS.5501 Part 1. These
refer to devices that do not generate or store more than 1.2V, 0.1Amp, 20 microJoule and 25 milliWatt.
They may be installed in a hazardous area relating to a classification EEx ia IIc T4. The reed-switch contact
rating is 1VA with a switching voltage of 24V ac/dc with contact arrangement normally open form A. For
the display please see the separate display instructions.
There is a technical construction file TCF004 containing an assessment against ATEX Directive 94/9/EC
Annex 2 for installation as equipment Group II Category 1G EEx ia IIC T5 Tamb = -40°C/+60°C. Suitability is
confirmed by ignition hazardous assessments for both electrical and non-electrical equipment.
FLAMEPROOF EExd – Installation notes
Mounted directly on the meter or indirectly is the IP66/IP68 enclosure providing rate and total display.
Please see separate instructions.
Pulse Output: Without a display the raw output may be utilised externally via the junction box.
PRESERVATION
Please note these flowmeters are generally constructed externally in stainless steel with stainless steel
instrument housings. They are designed to be at least IP67 and are, therefore, suitable for mounting
outside to that limit. We would normally recommend that the lowest temperature be –20°C. Please
contact factory if this is likely to be lower. We would also recommend that no fluid be left in the flowmeter
if there is a likelihood of the fluid freezing or setting. If some fluids leave residue, we recommend that
these are thoroughly cleaned out before the units are stored. They will be shipped drained of calibration
and test fluids. If they are to be left for extended periods of time without fluids, then the humidity should
be controlled and either a preservative used inside the meter to prevent any corrosion effect or fully dried.
Please ask the factory for advice. If the display cover is removed, we recommend maintaining the humidity
at less than 40% RH to prevent component corrosion. We do not recommend that demineralised or de-
ionised water is left in the meter for more than a few days. In some rare cases, there has been some attack
on close-fitting surfaces. Either ensure the line is empty of fluid or use a preservation fluid.
RECALIBRATION PERIOD
Recalibration periods of flowmeters are based on industry standards. In industrial applications,
depending on the industry, periods of 6 to 12 months are recommended. Litre Meter advise the user to
seek out data relating to the process, other components within the process and the usage of the meter. If
the measurement is critical then the recalibration should be more frequent than a non-critical rarely used
device. In the absence of any other data Litre Meter advise an annual check and to vary the future
calibration periods depending on results.
If it has remained unused, then no recalibration will usually be necessary. It is wise to check that no fluid
has settled in the measurement chamber that might alter the way the rotor rotates or even cause slight
corrosion where two metal surfaces have been in close contact. Once cleaned the performance should
remain unchanged.
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