Hydronic Manometer HM685 by TSI Alnor - Pressure & Flow Measurement

Area Monitoring Datalogging
Heating, Ventilation & Air Conditioning (HVAC) Manufacturer: TSI Alnor
Hydronic Manometer HM685 by TSI Alnor - Pressure & Flow Measurement
Hydronic Manometer HM685 by TSI Alnor - Pressure & Flow Measurement
Hydronic Manometer HM685 by TSI Alnor - Pressure & Flow Measurement

The TSI Alnor HM685 is a professional-grade hydronic manometer that simultaneously measures and displays differential pressure, high-side gauge pressure, and low-side gauge pressure, all without changing hose connections or valve settings. By entering a valve manufacturer's Cv or Kv flow factor, the HM685 calculates volumetric flow rates up to 99,999 GPM. Additional capabilities include built-in data logging, dual temperature measurement ports, USB connectivity, and advanced calculation modes for pump laws and heat flow analysis. Ideal for balancing and troubleshooting steam and hot water heating, chilled water cooling, and hydronic pump performance systems.

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$475.00
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What is the TSI Alnor HM685 Hydronic Manometer used for?
It's a digital differential pressure manometer for measuring pressure differential, flow rate, and temperature in hydronic HVAC systems. It's used during commissioning, balancing, and troubleshooting of chilled water, hot water, and condenser water systems to verify coil and valve flow rates.
How does the HM685 calculate flow in a hydronic system?
It measures differential pressure across a coil, valve, or other component with known pressure-flow characteristics, then uses the pressure-flow relationship for that component to calculate flow. It includes a built-in library of common coil and valve data for direct flow calculation.
HM685 vs. ultrasonic clamp-on flow measurement — when should I use each?
Use the HM685 when pressure taps are already installed on coils or valves you're balancing, and you want fast direct flow readings using the instrument's coil/valve database. Use an ultrasonic clamp-on meter (like the Panametrics PT900) when taps aren't available or when you need non-intrusive pipe flow measurement across the broader system.
What's a common mistake when measuring hydronic flow with the HM685?
Using an incorrect coil or valve selection from the instrument's library, or connecting to the wrong pressure taps. Verify the component ID and confirm you're connected to the correct supply and return taps for the specific coil or valve being measured.
What should I confirm before deploying the HM685?
That pressure taps are installed and accessible on your target coils/valves, that the component is in the instrument's library, and the expected flow range is within the instrument's measurement capability.
What does it cost to rent the TSI Alnor HM685?
Contact RAECO Rents for current daily and weekly rates. For hydronic balancing projects covering multiple AHUs, coils, or buildings, the weekly rate is typically more economical than daily — most meaningful balancing campaigns span several days.

Features & Capabilities

Datalogging: ✓ Yes
Monitoring Scope: Area Monitoring

Equipment Specifications

Type/Class Rating: Hydronic Differential Pressure Manometer
Measured Parameters: Differential Pressure, High-Side Gauge Pressure, Low-Side Gauge Pressure, Flow Rate (calculated), Temperature (with probes)
Measurement Range: Differential Pressure: ±300 psi (±2068 kPa); Gauge Pressure: -20 to 300 psi (-138 to 2068 kPa); Flow: up to 99,999 USGPM (calculated via Cv/Kv valve flow factor); Temperature Probe: -40 to 250°F (-40 to 121°C)
Resolution: 0.001 psi, 0.0001 USGPM, 0.1°F (0.1°C)
Accuracy: ±1% of reading +0.072 psi; Flow: ±0.5% of reading +1.2°F
Connectivity: USB via TSI CompuDat software (included free with rental)
Compatible Probes / Accessories: Dual temperature measurement ports, Built-in coil/valve Cv/Kv library
Data Logging Capacity: 100 test IDs, up to 4,000 readings with time/date stamp
Battery Run Time: 4 AA batteries (alkaline or NiMH); ~12 hours with backlight, ~18 hours without

Kit Contents

TSI HM685 Hydronic Manometer, blue and red hose kit, shut-off valves (1 red, 1 blue), two blue flow restrictor connectors, HMFIT accessory kit with various adapters, B&G readout probes and P/T gauge adapter probes, temperature probe, AC adapter, mini USB cable, CompuDat software/manual/quick start guide on flash drive, and 4 spare AA batteries

Manufacturer Resources

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