TSI DP-Calc 5825 Micromanometer for Duct and Filter Pressure

A pressure-only handheld for filters, ducts and cleanrooms

The TSI DP-Calc 5825 is a handheld micromanometer. It measures static and differential pressure to 0.1 Pa resolution and turns a pitot tube reading into air velocity and, with a duct size or a manufacturer K-factor, into volumetric flow. There are no velocity or humidity probes: everything works through two pressure ports.

That narrow scope suits technicians who check filter pressure drop, duct static pressure, room pressurisation and pitot traverses and want a robust meter with logging. For hot-wire velocity or IAQ work see the other instruments under Portable Test & Measurement.

Features listed in the manual

• Pressure zeroing from the menu after a five-minute warm-up.
• Flow set-up modes Round Duct, Rectangle Duct, Duct Area and K-Factor, with up to 5 K-factors stored for quick recall.
• Actual/standard conversion, with barometric pressure entered by the user and an entered temperature of -40 to 1832 F (-40 to 1000 C).
• Manual, Auto-save and Cont-key logging; keypad lock for unattended logging.

Technical specification

Pressure and velocity

Logging, physical and power

Where the 5825 fits

Choose the 5825 for pressure-based work: it has no temperature or humidity measurement, so velocity from a pitot tube uses the entered temperature. If you need to read air velocity directly, humidity or CO2, the 9545 and 9565 are better matches. The sister model 8715 shares a different manual and is not described here.

Zeroing, connections and logging

Warm the instrument for at least five minutes, then run Pressure Zero. The manual notes that Pressure Zero reports whether the zero was successful. Connect the supplied tubing from the static pressure tip or pitot probe; the instrument can be damaged above its 7 psi overpressure limit.

Because temperature is not measured, the actual barometric pressure must be entered to convert velocity and volume to actual conditions. When Flow is the primary reading the duct dimensions or K-factor appear on the screen and can be changed with the arrow keys. The manual recommends annual factory recalibration and offers field adjustment only for minor changes.

Samples are grouped into Test IDs (up to 100), each with average, minimum, maximum and count, so one duct traverse or one filter check can be stored as one Test ID. The time constant works as a moving average that dampens the display: with 10 seconds selected the screen still updates every second but shows the mean of the last ten. Clean the case with a soft cloth and isopropyl alcohol or mild detergent, never immerse it, and remove the batteries before storing the meter for more than a month.

Typical filter, duct and room-pressure tasks

In Gulf plants the 5825 is suited to checking pre-filter and final-filter differential pressure on AHUs, duct static pressure on supply fans, and pressure differentials between a control room and surrounding spaces. Keep it inside its 5 to 45 C operating range and out of direct sun on rooftop units.

Included and related items

The manual lists the carrying case, pressure tubing, static pressure tip and USB cable as supplied, with LogDat2 software for downloading data. Pitot probes are not listed in this manual, so confirm which pitot and tubing you need when you send an RFQ. Application Note TSI-114 is referenced for K-factor flow.

Selection and installation notes

Handheld air and environment meters are selected from the quantity measured, the range and the accuracy needed. Let the probe settle in the air stream, take readings at the points and the number the test method requires, keep the sensors clean, check the battery before a survey and keep the calibration current according to your quality system. Note the conditions and the probe position with every reading so the survey can be repeated.

Information needed for a quotation

Send the full model code, the quantity, the delivery location in Oman or the GCC, the intended use and any accessories needed, so that the complete package can be quoted together.

Documents and supply information

The manufacturer data sheet is attached to this page and should be read together with the project specification and the site risk assessment before a purchase is confirmed. Ratings, standards and dimensions are quoted as printed on that sheet. Lead time, stock position and certificates available with the shipment are confirmed in the quotation, and we supply to Oman and the wider GCC region for industrial, utility and building services projects.

Frequently asked questions

What pressure range does the 5825 cover? Minus 15 to plus 15 in. H2O, which is minus 3735 to plus 3735 Pa.

What is the overpressure rating? 7 psi (190 in. H2O); higher pressure can damage the sensor.

Can it calculate flow from a diffuser? Yes, with a K-factor from the diffuser or flow station maker; up to 5 K-factors can be stored.

Does it measure temperature? No. Temperature for actual-condition conversion is entered by the user.

Is Seven Star LLC a TSI distributor? No. This is an independent supply offer from Seven Star LLC in Muscat, not a distributor listing.

Documents and quotation

TSI publishes the attached manual (P/N 1980568 Rev H, November 2024). Send us your RFQ with the exact model and any probes or options so we can confirm availability. No price is listed here.