This page is “Under Construction” and will be for some time. Check back periodically.

This section of the site is intended to provide hygienists with practical tips on the care and maintenance of their equipment to ensure that it provides maximum service life. Here we will describe simple procedures that will keep your equipment running as long as possible.   We will also describe simple repairs that can be done either in the field or in the office with simple tools.

Equipment Repairs

The repair tips we will offer here are not meant for those with limitless equipment budgets, but rather for those that want to stretch limited budgets as much as possible and use their equipment dollars to increase measurement capabilities rather than to replace equipment they already have.

The section will also contain a number of simple tips and techniques garnered from our years of field practice that may simplify  your hygiene measurements.

We will provide links to pages showing you how to fix a piece of occupational hygiene equipment, by diagnosing and repairing common faults in sampling pumps and direct reading instruments. In order to benefit from these instructions it is important that you know your equipment intimately.

The first thing you should do when you acquire a new piece of equipment is to read the operation manual. The second thing you should do is read the manual again. If and when a fault occurs, or when you are about to use equipment you haven’t used for some time, read the manual again.

The manual will often give a reason for the fault and provide step by step instructions to remedy it. In many cases you will not be able to repair a fault and the equipment will have to be returned to the manufacturer or an authorized repair facility, but it is surprising how many problems can be fixed by the end user if they are familiar with the information supplied in the equipment manual.

If you have inherited equipment from the previous person in your present position, you may not have a printed manual or know where to find it. In this case, you should go to the manufacturer’s web site and search for their manuals page. Most have PDF versions of their manuals available for download. Even if you have a printed copy of a manual, you should still download a PDF version as backup. I maintain a library of equipment manuals on my computer for all of the equipment I own or have owned. It is usually faster to find what I want in this digital library than digging through an overstuffed filing cabinet for the printed version.

We have run ALARA using equipment, much of which would be considered hopelessly outdated by new entrants to the health and safety field.  As an example. most of our sampling pumps were acquired 25-30 years ago in the early days of our business and are still running reliably. This is primarily because they received regular maintenance and minor repairs when needed. Our experience has been that if equipment is chosen judiciously and given a reasonable amount of care, there is no reason for it to need replacement in a shorter period unless it is superseded by newer (and necessary) technology.


The one thing that will require replacement, of course will be the equipment’s rechargeable batteries. Most older portable hygiene equipment was powered by rechargeable nickel-cadmium batteries. Later, some manufacturers introduced nickel-metal hydride rechargeables which offered higher energy densities (the same or longer run times from smaller cells). After lithium-ion cells became the standard in laptop computers and cell phones, some manufacturers began offering hygiene sampling pumps and other equipment with lithium-ion batteries.  These have even higher power densities than NiMH batteries and are partially responsible for the present generation of small and light weight equipment. No rechargeable battery lasts forever. All have a limited number of charge-discharge cycles before they will no longer run for an 8-hr workshift.

We cannot do anything about the size of our older equipment, but we can dramatically reduce the weight and extend the run times of older equipment by replacing the old Ni-Cads with NiMH or lithium rechargeable batteries (when available). We can also save a considerable amount of money by rebuilding or having someone else rebuild these batteries for us.

I intend to include illustrated instructions for how this can be done for a number of sampling pump models and other pieces of battery operated equipment, along with caveats about the process. This should be of particular interest to occupational health professionals in the developing world where funds are constrained and access to replacement batteries and other replacement parts may be difficult. I have been rebuilding battery packs for my equipment for about 25 years and have found that the rebuilt batteries easily match or exceed the originals for number of charge-discharge cycles and run-time per charge at a small fraction of the cost of exact replacements.

Check back periodically over the next few months as we add pages on this and other topics to the website.