Analyse EasyLog Data Online — Ragged Rows, Odd Degree Signs and All

Read as delimited textNo dedicated reader yet. The generic one copes with the two things that stop other software — the ragged rows and the arbitrary first heading — and one column comes through that should not.

An EL-USB logger is the cheapest way to find out what a store room, a shipping crate or a greenhouse actually did overnight, and its CSV is the plainest file on this whole section of the site. It also has three small oddities that make strict software refuse it outright. Here they are, and here is what happens to them.

Drop it here

Open the resampler and drag the file onto it — as it came off the logger, header lines and all. It reads the file in this browser tab: nothing is uploaded, there is no account, and no request goes out while you work.

Open the file reader

What the export looks like

North store room,Time,Celsius(°C),Humidity(%rh),Dew Point(°C),Serial Number
1,2023-10-19 12:00,18.5,52.0,8.4,00042318
2,2023-10-19 12:30,18.6,51.5,8.3
3,2023-10-19 13:00,18.9,51.0,8.3

Line 1 IS the header — there is no title line. The first heading is whatever you called the logger, so it is different in every file. Note that rows 2 and 3 are a field short: the serial only appears once, and the trailing empty field is simply absent rather than written as a comma. The degree signs are shown here as they are meant to read; in the file itself they are a Windows-1252 byte, which is why they so often arrive as a question mark or a black diamond.

The awkward parts, and what happens to them

The first column heading is arbitrary user text — the name you gave the logger — so no two files agree on it.: Nothing keys on it. The timestamps are found by the Time column and by what the column contains, not by a heading anybody could have typed.
Ragged rows. Where a trailing field is empty it is left out entirely, so most rows have five fields where the header has six. A strict CSV reader refuses the whole file.: Read leniently. A short row is a row with a missing value at the end of it, not an error.
The degree sign is a Windows-1252 byte rather than UTF-8, so the heading arrives mojibaked — Celsius(° C) becomes Celsius(? C) or worse.: Matched on the readable part of the heading rather than on the whole string, so a mangled degree sign does not lose you the column.
The Serial Number column carries a value on the first row only, and may have leading zeros.: Kept as a channel today, which is wrong but harmless — it is metadata, not a series, and it appears in the channel list with one reading in it. Ignore it, or delete the column before dropping the file in.

Every line above is asserted by src/core/timeseries/__tests__/vendorFallback.test.ts, which runs on every change to this site’s code.

What has not been checked

Everything here describes the EL-USB desktop export from EasyLog. The EasyLog CLOUD export and the EL-WiFi range have not been checked at all, and nothing on this page should be read as describing them. If you have one it will still be read as ordinary delimited text; it just has none of the knowledge above behind it.
The Fahrenheit heading wording has not been verified either. A Celsius file is the one that was checked, and rather than hard-code a guess at what the Fahrenheit variant says, nothing here matches on it — which means a Fahrenheit file is read as numbers with an unrecognised unit rather than being converted for you.

The serial-number column, and why it is still there

The Serial Number column is metadata: one value, on the first row, describing the whole file. A column of numbers is a column of numbers as far as a general-purpose reader is concerned, so it comes through as a channel with a single reading in it.

That is recorded in the test suite as a thing that happens rather than as a thing that is desirable, which is the difference between a known limitation and a bug nobody has noticed. A reader written specifically for EasyLog would lift it onto the file rather than into the channel list, and when one exists this paragraph goes away.

What an EL-USB record is usually for

Temperature, humidity and a dew point the logger worked out for you, at a fixed interval, for as long as the battery lasted. The two questions people bring to one of these are almost always "how warm did it get, and for how long" and "did it ever get near condensation".

The dew point in the file is the logger’s own. If you want to check it, or you want the depression between it and the air temperature, the dew point tool recomputes it from the temperature and humidity columns using a stated and cited equation — and if the two disagree by a few hundredths of a degree, that is the two equations differing rather than either being wrong.

Common questions

EasyLog says my file is corrupt, but a text editor opens it fine.: Then the readings are there and you do not need EasyLog to get at them. Drop the file in here; the ragged rows and the odd characters that upset strict readers are handled.
Why is there a channel called Serial Number with one reading in it?: Because it is a column of numbers and nothing here knows yet that it is metadata. It is harmless — ignore it, or delete the column first. It is on the list to fix.
Does my data get uploaded?: No. It is read in your own browser tab, and there is nowhere on this site to upload anything to.