Summary of the content on the page No. 1
TELEDYNE
HASTINGS
INSTRUMENTS
INSTRUCTION MANUAL
HFM-300 FLOW METER,
HFC-302 FLOW CONTROLLER
Summary of the content on the page No. 2
Manual Print History The print history shown below lists the printing dates of all revisions and addenda created for this manual. The revision level letter increases alphabetically as the manual undergoes subsequent updates. Addenda, which are released between revisions, contain important change information that the user should incorporate immediately into the manual. Addenda are numbered sequentially. When a new revision is created, all addenda associated with the previous revision of the
Summary of the content on the page No. 3
Table of Contents 1. GENERAL INFORMATION............................................................................................................................................ 4 1.1. FEATURES.................................................................................................................................................................... 4 1.2. SPECIFICATIONS.................................................................................................................
Summary of the content on the page No. 4
1. General Information The Teledyne Hastings HFM-300 is used to measure mass flow rates in gases. In addition to flow rate measurement, the HFC-302 includes a proportional valve to accurately control gas flow. The Hastings mass flow meter (HFM-300) and controller (HFC-302), hereafter referred to as the Hastings 300 series, are intrinsically linear and are designed to accurately measure and control mass flow over the range of 0-5 sccm to 0-10 slm with an accuracy of better than ±0.75
Summary of the content on the page No. 5
1.2. Specifications Accuracy .................................................................................... < ±0.75% full scale (F.S.) at 3σ (±1.0% F.S. for >10 slm versions) Repeatability .............................................................................±0.05% of reading + 0.02% F.S. Maximum Pressure........................................................................................500 psi [3.45 MPa] (With high pressure option) 1000 psi [6.9 MPa] Pressure Coefficient
Summary of the content on the page No. 6
The 4-20 mA I/O option can accept a current input. The 0-5 VDC command signal on pin 14 can be replaced by a 4-20mA command signal. The loop presets an impedance of 75 ohms and is returned to the power supply through the valve common. 1.4. Other Accessories 1.4.1. Hastings Power Supplies Hastings power supplies are available in one or four channel versions. They convert 115 or 230 VAC to the ±15 VDC required to operate the flow meter. Interface termina
Summary of the content on the page No. 7
2. Installation and Operation This section contains the steps necessary to assist in getting a new flow meter/controller into operation as quickly and easily as possible. Please read the following thoroughly before attempting to install the instrument. 2.1. Receiving Inspection Carefully unpack the Hastings unit and any accessories that have also been ordered. Inspect for any obvious signs of damage to the shipment. Immediately advise the carrier who delivered the shipment if any dam
Summary of the content on the page No. 8
2.4. Mechanical Connections 2.4.1. Filtering The smallest of the internal passageways in the Hastings 300 is the diameter of the sensor tube, which is 0.026”(0.66 mm), and the annular clearance for the 500 sccm shunt which is 0.006"(0.15 mm) (all other flow ranges have larger passages), so the instrument requires adequate filtering of the gas supply to prevent blockage or clogging of the tube. 2.4.2. Mounting There are two mounting holes (#8-32 thread) in the bottom of the transducer tha
Summary of the content on the page No. 9
Fig. 2.1 Fig. 2.2 Figures 2.1/2.2, and Tables 2.1/2.2, show the 300/302 pin out. Table 2.1 Table 2.2 "U" Pin-Out "H" Pin-Out Pin # Pin # 1 Signal Common 1 Do not use 2 Do not use 2 Do not use 3 Do not use 3 Do not use 4 +15 VDC 4 Do not use 5 5 Signal Common 6 Output 0-5 VDC (4-20mA) 6 Output 0-5 VDC (4-20mA) 7 Signal Common 7 Case Ground 8 Case Ground 8 Valve Override 9 Valve Override 9 -15VDC 10 10 Do not use 11 -15VDC 11 +15VDC 12 External Input 12 Signal Common 1
Summary of the content on the page No. 10
2.6.2. Zero Check Turn the power supply on if not already energized. Allow for a 1 hour warm-up. Stop all flow through the instrument and wait 2 minutes. Caution: Do not assume that all metering valves completely shut off the flow. Even a slight leakage will cause an indication on the meter and an apparent zero shift. For the standard 0-5 VDC output, adjust the zero potentiometer located on the inlet side of the flow meter until the meter indicates zero (Fig 2.3). For the optional
Summary of the content on the page No. 11
Span Error Vs. Pressure Fig. 2.5 0.017" Sensor 5% 4% 3% 2% 1% 0% Mean Max -1% Min -2% 0 100 200 300 400 500 600 700 800 900 1000 Pressure (psig) If the system pressure is higher than 250 psig (1.7 MPa) the pressure induced error in the span reading becomes significant. The charts above show the mean error enveloped by the minimum/maximum expected span errors induced by high pressures. This error will approach 16% at 1000 psig. For accurate high pressure measurements this error must be
Summary of the content on the page No. 12
External Input pin (See Tables 2.1 & 2.2), the ratio of flows can be maintained over the entire range of gas flows. EXAMPLE: Flow controller A has 0-100 slpm range with a 5.00 volt output at full scale. Flow controller B has 0-10 slpm range with a 5.00 volt output at full scale. If flow controller A is set at 80 slpm, its output voltage would be 4.00 volts (80 slpm/100 slpm x 5.00 volts = 4.00 volts). If the output signal from flow controller A is connected to the command Set Point of f
Summary of the content on the page No. 13
On the controller card there is a jumper that sets whether the control loop controls mass flow or an external process variable. See Figure 2.7. If the jumper is over the top two pins, the loop controls mass flow. If the jumper is over the bottom two pins, the loop controls an external process variable. This process variable signal must be supplied on pin 12 of the D connector (for U pin out units) of the measurement card. When the controller is set for external variable control it will
Summary of the content on the page No. 14
2.12. Temperature Coefficients As the ambient temperature of Fig. 2.8 the instrument changes from the original calibration temperature, errors will be introduced into the output of the instrument. The Temperature Coefficient of Zero describes the change in the output that is seen at zero flow. This error is added to the overall output signal regardless of flow, but can be eliminated by merely adjusting the zero potentiometer of the flow meter/controller to read zero volts at z
Summary of the content on the page No. 15
3. Theory of Operation This section contains an overall functional description of the Hastings 300 series of flow instruments. In this section and other sections throughout this manual, it is assumed that the customer is using a Hastings power supply. 3.1. Overall Functional Description The Hastings 300 meter consists of a sensor, base, and a shunt. In addition to the components in a meter, The 300 controller includes a control valve and extra electronic circuitry. The sensor is c
Summary of the content on the page No. 16
can be dissipated by radiation, conduction, or convection. The radiation term is negligible due to the low temperatures used by the sensor, and because the sensor construction preferentially favors the conductive and convective heat transfer modes. The thermal energy of each heater will then be dissipated by conduction down the stainless steel sensor tube, conduction to the insulating foam, plus the convection due to the mass flow of the sensed gas. Because great care is taken to wind the
Summary of the content on the page No. 17
heater to the gas stream will force the upstream bridge control loop to apply more power to the o upstream heater so that the 48 C constant differential temperature is maintained. The gas stream will increase in temperature due to the heat it gains from the upstream heater. This elevated gas stream temperature causes the heat transfer at the downstream heater to gain heat from the gas stream. The heat gained from the gas stream forces the downstream bridge control loop to apply less power
Summary of the content on the page No. 18
desired to ensure a stable instrument, there must be some matching between the linear volumetric flow versus pressure drop of the sensor and the shape of the volumetric flow versus pressure drop of the shunt. Most instruments employ Poiseuille’s law and use some sort of multi-passage device that creates laminar flow between the upstream sensor inlet and the downstream outlet. This makes the volumetric flow versus pressure drop curve primarily linear, but there are other effects which
Summary of the content on the page No. 19
Qρ L = (3.5) e 5πμ For a typical flow divider tube the entry length is approximately 0.16 cm. From this it can be seen that if the sensor inlet pickup point is inside of the flow divider tube but downstream of the entrance length and if the sensor outlet point is inside the flow divider tube but upstream of the exit point then the pressure drop that drives the flow through the sensor would be linear with respect to volumetric flow rate. Since the pressure drop a
Summary of the content on the page No. 20
Fig. 3.5 Thickness of the annular ring as a function of flow rate for a sensor with a 75 Pa drop and a 2 cm spacing. 0.18 0.16 0.14 0.12 0.1 0.08 0.06 0.04 0.02 0 0 5 10 15 20 25 30 35 Flow (liter/min) Each shunt must have a section of the annular region upstream of the upstream sensor tap to allow the flow to become fully developed before reaching the first tap. The entry length for the annular passage is then: Qρ() Δr
