H&D Fitzgerald

+44 (0) 1352 720 774
ruen

Frequently Asked Questions about Liquid Density Standards

Why do I need Liquid Density Standards?

Some manufacturers of density meters recommend that calibration by air and water is acceptable. However, this is normally an adjustment, not a calibration, and while it is doubtful as to whether this meets the requirements of GLP (Good Laboratory Practice), it certainly does not give a calibration traceable to recognised national standards. Using our traceable standards correctly gives a traceable calibration.

Back to top.

How are standards supplied?

All our standards are supplied in a ~10ml sealed glass ampoule, and are sufficient to carry out the calibration of a laboratory density meter.  They are specially packaged so that they can be sent by mail, courier, or as air freight.

Back to top.

Which standards do I need, and how many?

You should ideally calibrate your density meter with two standards, with densities either side of the range in which you are working.

Although many modern density meters are very good instruments, not all density meters show linear behaviour over their entire measurement range. It is therefore good practice to restrict the calibration as far as possible to the density range over which the meter will be used.

It is much more advisable to calibrate using standards which bracket the working range rather than the entire range of the meter as specified by the manufacturer. This reduces your reliance on the linearity of the instrument, and will ensure smaller errors.

You should also note that the displayed density on many meters is affected by the viscosity of the liquid. If you are measuring viscous liquids, you should consider calibrating your meter with a CRM of similar viscosity.

Aqueous standards require more skill to handle, so we do not recommend you use them unless fiscal or safety authorities require you to do so.

The quantity of standards necessary will depend upon how often you wish to carry out calibration. All our standards are supplied in ~10ml ampoules, and this quantity is sufficient to fill the cell of most laboratory density meters.

We also calibrate entire batches of liquid standards to meet a clients’ specific requirements. Please contact us to discuss this

Back to top.

What is the delivery time?

The majority of our standards are available from stock. Orders can be processed as soon as they are confirmed.

Back to top.

Are standards available in other containers or quantities?

We do not supply larger ampoules or standards in re-sealable containers, as once a calibrated liquid is exposed to its surrounding atmosphere, it will begin to absorb air or moisture. This will alter the density.

Back to top.

Are MSDS data sheets available?

Materials Safety Data Sheets for each of our standards are available on this website — see MSDS for more information.

Back to top.