Best digital manometer for gas tightness testing (UK, 2026)
Digital gas manometers compared on resolution, range, built-in tightness tests and price, with the IGEM/UP/1B Edition 4 rules that decide whether a gauge movement counts.
Quick picks
| If you want | Look at | Why | Price |
|---|---|---|---|
| Lowest price | Sauermann Si-PM3 | Lowest price we could verify in this comparison. | £75.84 inc VAT |
| Finest resolution and automatic tightness test | Kane 3500-2 | 0.003 mbar resolution up to ±19.999 mbar (Kane datasheet) and automatic tightness testing. | £312.00 inc VAT |
| Timed tightness test with app reports | Anton APM145 | Timed let-by, stabilisation and tightness tests with adjustable pass/fail limits, and Wi-Fi to the Sprint app. | £202.80 inc VAT |
| Cheapest 2-decimal gauge (phone required) | Testo 510i | 0.01 hPa resolution, but readings show on your phone, not on the gauge. | £124.20 inc VAT |
Side by side
| Product | Key specs (published) | Standards / servicing | Price |
|---|---|---|---|
| Sauermann Si-PM3 |
| — | £75.84 inc VAT |
| Testo 510i |
| — | £124.20 inc VAT |
| Martindale PM85 |
| — | £131.40 inc VAT |
| Anton APM 135 |
| — | £139.20 inc VAT |
| Anton APM145 |
| — | £202.80 inc VAT |
| Kane DPM |
| — | £214.80 inc VAT |
| Kane 3500-2 |
| Meets EN 50725 (Kane site) | £312.00 inc VAT |
What matters when choosing
Resolution and IGEM/UP/1B Edition 4
IGEM/UP/1B Edition 4 was published in March 2026. Gas Safe Register's Industry Standard Update 133 (Edition 2, 15 April 2026) says Edition 3 ran alongside it until 30 September 2026. Under Edition 4, "no perceptible movement" means up to 0.25 mbar on a fluid (water) gauge or an electronic gauge reading to two decimal places, and up to 0.2 mbar on an electronic gauge that reads to one decimal place. A 2-decimal gauge shows smaller movements, so you can see a drop clearly.
Check resolution at your test pressure
Several gauges switch to a coarser resolution higher up the range. The Anton APM 135 and APM145 read 0.01 mbar up to 19.99 mbar, then 0.1 mbar. The Kane 3500-2 reads 0.003 mbar up to ±19.999 mbar, then 0.01 mbar. If your tightness test pressure is above 20 mbar, read the resolution for that band, not the headline figure.
Permissible drop now depends on installation volume
Under Edition 4, where there is perceptible movement with existing appliances connected, you work out the installation volume (IV) and compare the drop with the permissible-limits table for the gas type. A gauge or app with a timed test and a clear pass/fail saves time on site, but you are still responsible for the IV and the result.
Calibration and temperature compensation
Kane charges £99 ex VAT a year to service and recertify its manometers, and Test-Meter offers a calibration certificate when you buy for £29–£35 ex VAT. Temperature compensation (listed for the Kane 3500 and Kane DPM) reduces drift when the gauge warms up or cools down during a test.
Screen or phone
The Testo 510i has no display, so every reading is on your phone. That suits app reports, but means a flat phone stops the test. The Kane, Anton, Martindale and Sauermann gauges have their own screens.
Sources: IGEM/UP/1B Edition 4 (IGEM); Gas Safe Register Industry Standard Update 133 (Edition 2, 15 April 2026).
FAQs
What resolution manometer do I need for a gas tightness test?
IGEM/UP/1B Edition 4 accepts water gauges and electronic gauges. Per Gas Safe Register ISU 133, "no perceptible movement" is up to 0.25 mbar on a water gauge or a 2-decimal electronic gauge, and up to 0.2 mbar on a gauge reading to one decimal place. Many engineers choose a 2-decimal (0.01 mbar) gauge to see small movements clearly.
What changed in IGEM/UP/1B Edition 4?
According to Gas Safe Register ISU 133, permissible pressure drops now depend on the installation volume rather than meter size alone. Any perceptible movement must also be shown not to come from the installation pipework, by retesting the pipework only. The procedure itself is broadly unchanged: let-by at 7–10 mbar for 1 minute, 1 minute of temperature stabilisation, then a 2-minute test.
How often should a gas manometer be calibrated?
Kane sells its manometer service and recertification as a yearly service (£99 ex VAT a year). Check the manufacturer's stated interval for other brands, and keep the certificate with your records.
Which is the cheapest digital manometer here?
Of the 7 products with a price we could verify, the lowest was the Sauermann Si-PM3 at £75.84 inc VAT (£63.20 ex VAT) from Test-Meter, checked 20 Oct 2026. Cheapest is not always best, so check the points above.
Did GasStack test these gauges?
No. We compare published specifications and prices from manufacturer and retailer pages, checked on the date shown. Always read the current standard and the instrument's manual.
More tools & test kit guides
Get the weekly "What changed" email
One short email a week: price changes, new tools, and one rule or warranty change that matters to gas, heating and plumbing engineers. Free. Unsubscribe any time.
Plus a free starter pack when you confirm: van stock checklist, service reminder templates and a late payment letter (PDF). What's in it