---
title: 12. K&A Next Gen Software - Flow Rates & Column Diagnostics
description: How to sample and calibrate flow rates on the Flow Rates screen in KA_Labs and use the results to spot a restricted line.
---
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August 27, 2026
# 12. K&A Next Gen Software - Flow Rates & Column Diagnostics
## How to sample flow rate per line, calibrate, and use the results to spot a failing line or column. Walkthrough video (4:08).
---
The **Flow Rates** screen lets you calibrate and record the measured flow rate of each reagent and amidite line on your K&A instrument. KA\_Labs uses these values to estimate reagent consumption, so keeping them current is what makes the **Estimate Volume** function accurate. Reviewing the values across all lines is also one of the quickest ways to spot a partially blocked line or a valve that needs service.
---
### Applies to
- All K&A H-series instruments (H-2 through H-32) running KA\_Labs software.
---
### When to use this
Check and recalibrate flow rates in any of these situations:
- About once per month, as part of routine preventative maintenance (PM).
- When you suspect a discrepancy in a line's dispense volume.
- After any valve replacement or tubing change that could affect delivery.
- When **Estimate Volume** results look inaccurate.
---
### Before you start
- The instrument is powered on, KA\_Labs is running, and no synthesis is in progress.
- A clean, dry graduated cylinder or tared collection vial to measure dispensed volume.
- Reagent and amidite bottles are installed and the lines have been primed, so each line is full and free of air. Priming is on the **Priming** screen.
- The lab is within the standard environmental range, including humidity below 50% RH.
---
### Open the Flow Rates screen
\[INSERT IMAGE: Screenshot of the Setup/Utilities tab with the Flow Rates screen open, showing the per-line flow rate values and the dispense duration field. Annotate the line list, the measured-volume entry, and the dispense control with numbered callouts.\]
1. In KA\_Labs, select the **Setup/Utilities** tab.
2. Open the **Flow Rates** screen. The screen lists each reagent and amidite line with its current recorded flow rate.
---
### Review flow rates as a diagnostic check
Before recalibrating, read the existing values. The pattern across lines tells you whether a line is healthy.
- Compare each line against the others. A line that reads noticeably lower than comparable lines is the first thing to investigate.
- Compare each line against its own history. A value that has drifted down from its previous calibration points to a developing problem on that line.
> **NOTE:** A flow rate that is significantly lower than its peers or its own historical value can indicate a partially blocked line, a worn membrane, or a valve in need of service. Treat a large discrepancy as a prompt to inspect that line, not just to re-enter a number.
---
### Calibrate a line
Calibration means dispensing a known volume from a line, measuring the actual output, and recording it so KA\_Labs has an accurate flow rate for that line. Repeat the procedure for each line you need to calibrate.
> **NOTICE:** Dispensing reagents and amidites involves solvents and reactive chemistries. Collect into an appropriate container, work in the instrument's normal ventilation, and follow your site's chemical handling procedures. Spilled or mishandled reagent can damage the instrument and waste costly amidite.
1. On the **Flow Rates** screen, select the line you want to calibrate.
2. Position the graduated cylinder or tared vial to collect the output from that line.
3. Confirm the dispense duration. The default reagent dispense time is **3.3 seconds**. Leave this at the default unless you have a specific reason to change it, because the value affects the measured result and downstream volume estimates.
4. Dispense the line for the set duration using the screen's dispense control. \[Confirm the exact on-screen button label against the current build before publishing.\]
5. Measure the volume actually collected.
6. Enter the measured volume into the line's entry field on the **Flow Rates** screen. KA\_Labs uses the measured volume and the dispense duration to calculate and store the flow rate for that line. \[Confirm whether the field expects the measured volume or a computed flow rate, and the exact save/update control label, against the current build before publishing.\]
7. Repeat for each remaining line.
> **NOTICE:** Flow rate values must be entered and current for **Estimate Volume** to produce accurate results. If a line has never been calibrated, its volume estimates will be unreliable.
---
### Verify the calibration
- The recorded flow rate for each calibrated line updates to a value consistent with comparable lines and with that line's history.
- Run **Estimate Volume** for a representative synthesis. The estimated reagent consumption should look reasonable for the run. If a single line's estimate is still off, recheck that line's measured volume entry.
---
### Troubleshooting
---
### Related articles
- [Prime reagent and amidite lines on the K&A (Priming screen)](https://support.sierrabio.com/ka-priming-screen?hsLang=en) \[confirm this slug exists; create or relink if not\]
- [Estimate reagent volume for a run on the K&A](https://support.sierrabio.com/ka-estimate-volume?hsLang=en) \[confirm this slug exists; create or relink if not\]
For help, contact [support@sierrabio.com](mailto:support@sierrabio.com).
---
*Last reviewed: 2026-06-25. Owner: Field Operations. Applies to: K&A H-series running KA\_Labs software.*
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