As you can see on Slide 4, total sales for the fourth quarter were $112.3 million compared to $107.6 million in the same period last year, an increase of 4%.
In utility water, overall sales increased 8% against a difficult comparison in Q4 last year, which was also up 8% over 2018.
The acquisition of s::can completed in November 2020 contributed approximately 3 points of the current quarter's revenue growth, with core organic revenues in utility water up 5% year-over-year.
As anticipated, flow instrumentation sales were sequentially less worse, down 10% year-over-year compared to the 18% decline experienced in Q3 2020, although activity levels continue to reflect the broadly challenged markets and applications served globally.
Operating profit as a percent of sales was 15.1%, a modest 10-basis-point decline from the prior year's 15.2% with a number of moving parts at the gross profit and SEA line that I will dissect in more detail.
Gross margin for the quarter was 39.2%, up 100 basis points year-over-year.
Currently averaging around $3.60 per pound, this represents over a 30% increase year-over-year.
To give you some level of sensitivity, if copper prices stay in this range for the entire year, it could be a potential cost headwind of about $4 million to $5 million year-over-year.
So these two months, as expected, totaled approximately $2.5 million in revenues.
As we look to 2021, the combination of s::can and ATi, with total acquired revenue of approximately $37 million, we expect to be earnings per share accretive.
Now that these plans appear more firm, we have taken this provision, which reduced gross margins in the quarter by approximately 300 basis points to cover future radio upgrades for these early cellular customers.
These first networks had been in service nearly 20 years at that point.
The fourth quarter's spend of $27.1 million increased $2.3 million from the prior year.
Including both s::can and ATi in 2021, we expect ongoing SEA as a percent of sales to average in the 25% to 26% range.
The income tax provision in the fourth quarter of 2020 was 22.6%, slightly lower than the prior year's 24.3% rate.
In summary, earnings per share was $0.45 in the fourth quarter of 2020, an increase of 7% from the prior year's earnings per share of $0.42.
Working capital as a percent of sales was 26%, with about 1% of that associated with the addition of s::can.
On an organic basis, primary working capital as a percent of sales declined about 200 basis points year-over-year.
Our full-year free cash flow of $80.5 million was 10% higher than the prior year's $73.2 million and represents approximately 163% conversion of net earnings.
Our cash flow focus will not abate and we anticipate free cash flow conversion to exceed 100% in 2021.
We ended the year with approximately $72 million of cash on the balance sheet after taking into account the s::can acquisition.
In early January, we deployed $44 million net of cash acquired for ATi, remaining in a net cash positive position.
Along with the continued full access to our untapped $125 million credit facility, we have ample financial flexibility to continue executing on our capital allocation priorities.
From a geographic standpoint, where ATi is strong in the US and UK, s::can has an installed base in 50 countries.
The combined acquired annual sales of approximately $37 million with EBITDA margins in the mid-teens will be earnings per share accretive to our results.
Despite the unprecedented backdrop of a health and economic crisis, we have delivered utility water revenue growth, SaaS revenue as a percent of sales growth to now 5%, strong EBITDA margin expansion, robust working capital management and cash flow and successful execution of two accretive acquisitions.

Summary:
As you can see on Slide 4, total sales for the fourth quarter were $112.3 million compared to $107.6 million in the same period last year, an increase of 4%.
In summary, earnings per share was $0.45 in the fourth quarter of 2020, an increase of 7% from the prior year's earnings per share of $0.42.