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『K24 Flow Meter Manual PDF: Calibrating Digital Turbine Instruments for Diesel Fuel and Urea Transfers』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
K24 Digital Turbine Flow Meter Calibration for Diesel and Urea Transfer
Quick Answer: K24 digital turbine instruments need a correct K-factor before use in diesel or urea transfer. K-factor is the number of pulses per liter or per gallon. A water calibration shifts the diesel K-factor by 2 to 5 percent. Use actual diesel or urea for calibration and enter the correct K-factor into the K24 menu. Send your pipe size (DN), flow range, and fluid type to Silver Instruments for a calibration advice.
In practice, many flow meter users skip the fluid specific calibration. They use the default K-factor from the manual PDF. The result is a wrong batch total. A paint manufacturer in Vietnam reported a 3 percent diesel over-read last year. The cause was a K-factor taken from a water calibration report. The K24 manual PDF covers the basic menu steps. This article adds field level guidance for diesel and urea transfers.
Understand the K24 Platform
The K24 digital turbine instrument from Silver Instruments works with pulse output turbine flow sensors. It displays flow rate and total. The manual PDF shows battery and 24 V DC power options. The K24 accepts 0 to 5 V pulses or contact closure. You enter the K-factor in pulses per liter or pulses per gallon. A password menu protects the calibration changes. Most field errors happen because the flow unit and K-factor unit do not match.
Turbine meters are sensitive to viscosity. Diesel viscosity ranges from 2.5 cP at 40°C to 6 cP at 0°C. Urea solution at 32.5 percent has a viscosity near 1.5 cP at 20°C. A K-factor from water at 1 cP will not be exactly correct for either fluid. That is why the K24 manual recommends a fluid specific calibration.
Calibration Basics for the K24 Digital Instrument
Here is the thing. Calibration means comparing the K24 total to a known volume or mass. The easiest field method uses a master flow meter in series. Run a known volume through both meters. Record the K24 total and the master meter total. Calculate the new K-factor with this equation. New K-factor equals old K-factor multiplied by reference volume divided by indicated volume.
For example, old K-factor is 10000 pulses per liter. The K24 indicated 102 liters. The master meter indicated 100 liters. New K-factor equals 10000 times 100 divided by 102. That gives 9803.9 pulses per liter. Enter that value into the K24 and repeat the test.
Do not calibrate with an empty pipe. Air bubbles cause the turbine to spin faster and give false pulses. Purge the line with the actual fluid for 10 minutes before starting a run. This step takes time but it prevents a half percent error. Most engineers skip this part and then wonder why the K-factor drifts.
Diesel Fuel Specific Calibration Points
Diesel has a lower vapor pressure than water. Air bubbles are common after filter changes or pump suction leaks. Install a strainer and an air eliminator before the turbine meter. The K24 has a damping function. Set damping to 1 second for normal transfer. For fast batch loading, use 0.5 seconds.
Calibration points for diesel should include 10, 25, 50, 75 and 100 percent of full scale. Record the K-factor at each point. The K-factor should stay within plus or minus 0.5 percent across the range. If the curve is not flat, use the K24 multi-point linearization. It supports up to 10 points. For custody transfer or fuel tax, multi-point calibration is safer. For process control, a single average K-factor works.
We have seen a diesel day tank feed in Saudi Arabia with a 5 percent over-read. The user calibrated with water. After a diesel calibration at 3 cP, the error dropped below 0.5 percent. Same meter, same K24, different K-factor. That is the power of fluid specific calibration.
Urea Transfer Specific Calibration Points
Urea solution is water based but not identical to water. The viscosity at 20°C is around 1.25 to 1.5 cP. That is close to water but still shifts the K-factor by up to 1 percent. Urea can form crystals below 0°C. These crystals can block the turbine rotor. In cold climates, keep the meter and pipe above 5°C. Use a 316 stainless steel turbine body with ceramic bearings or PVDF rotor support. Silver Instruments recommends the TUF-10 or TUF-15 turbine sensor with 316 stainless steel body for urea.
After a urea transfer, flush the meter with demineralized water. Do not leave urea in the flow meter overnight. Residual urea crystallizes and damages the rotor. The K24 low flow cutoff should be set at 1 percent of full scale. This stops the totalizer from counting false pulses caused by vibration.
Field Calibration Procedure Step by Step
Step 1. Install a master met
Step 2. Fill the line, remove air, and run at a constant flow for 10 minutes. Temperature matters. Diesel viscosity changes with temperature. Record fluid temperature.
Step 3. Reset the K24 totalizer to zero. Start the test run. Stop after a known volume passed. Record the K24 total and reference volume.
Step 4. Calculate the new K-factor with the equation above. Enter it into the K24 menu and save.
Step 5. Repeat the test at two other flow rates. The repeatability should be within 0.2 percent. If not, check for air leaks, insufficient straight pipe, or a damaged rotor.
Straight pipe requirements: minimum 10D upstream and 5D downstream. Use a 60 mesh strainer upstream for both diesel and urea. Do not use a flexible hose directly at the meter inlet. Pulsation from positive displacement pumps also affects turbine accuracy. Install a pulsation dampener if the pump has a high pulsation rate.
Recommended Silver Instruments Configurations
For diesel transfer up to 120 L/min, use a DN15 or DN20 Silver Instruments turbine flow meter. Pair it with the K24 digital instrument. A pulse output of 10 pulses per mL is common for diesel. That equals 10000 pulses per liter. Make sure the K24 input type matches the pickup. Our pulse output is open collector NPN. Connect through a 4.7 kOhm pull up resistor. The K24 accepts 0 to 5 V pulses or contact closure.
For urea, use a DN10 or DN15 meter with 316 stainless steel body. We can supply a factory calibration with actual diesel or urea at our Nanjing facility. Most customers order a 5-point calibration certificate for diesel viscosity at 3 cP and urea at 1.5 cP. Standard accuracy after calibration is plus or minus 0.5 percent of rate. Linear range is 10 to 100 percent of full scale.
Model pairing: K24 digital instrument with TUF-15 turbine sensor for diesel. TUF-15 covers 2 to 100 L/min. For urea, TUF-10 covers 1 to 50 L/min. Both sensors have pulse and 4-20 mA output options. The K24 manual PDF includes wiring diagrams for both power options.
Common Calibration Problems and Fixes
Problem 1. K-factor entered in wrong unit. If the K24 unit menu is set to gallons but the K-factor is pulses per liter, the total is wrong by 3.785. Always confirm flow unit first.
Problem 2. Viscosity not considered. A water calibration for diesel or urea gives a wrong K-factor. Use the actual fluid for calibration.
Problem 3. Pulsation from a pump. Turbine meters cannot handle high pulsation. Install a pulsation dampener downstream of the pump.
Problem 4. Magnetic pickup gap too wide. The signal becomes intermittent at low flow. Set the gap to 1.5 mm for K24 sensors with magnetic pickup.
Problem 5. Electrical noise from diesel transfer pumps. Use shielded cable and ground the shield at the K24 end only.
FAQ
1. Can I calibrate a K24 digital turbine meter with water and use it for diesel?
No. Water calibration shifts the K-factor for diesel by 2 to 5 percent because viscosity differs. Use actual diesel or a fluid with matched viscosity. If water calibration is the only option, accept a possible error and recheck with actual diesel later.
2. What is the typical K-factor for a K24 turbine flow meter in diesel?
For a DN15 meter with 10 pulses per mL, K-factor is around 10000 pulses per liter. For DN20, around 5000 pulses per liter. Always use the value from the calibration certificate.
3. How often should I recalibrate a K24 turbine meter for urea transfer?
Every 12 months or after 100,000 liters, whichever comes first. Urea can build deposits on the rotor. Cleaning and recalibration restore accuracy.
4. What pipe size do I need for a 30 L/min diesel transfer?
DN15 is enough for 30 L/min with 10D upstream straight pipe. If viscosity rises above 5 cP, consider DN20 to reduce pressure loss.
5. Does the K24 manual PDF cover Modbus or 4-20 mA output?
The K24 manual covers pulse input, scaling, and relay outputs. It does not cover Modbus. Silver Instruments can provide a separate 4-20 mA output board or RS485 Modbus version if needed.
Send us your pipe size (DN), flow range in L/min, fluid type (diesel or urea), temperature, and required accuracy. We will recommend the correct K24 digital turbine instrument and factory calibration. Contact Silver Instruments at Tel: +86-25-68650347, WhatsApp: +86-25-52155837, WeChat: +86 15365082610. Visit flow-meter.com.au for more flow meter options. We respond within 12 hours for Asia Pacific and Middle East inquiries.