Red Lion PAXLPV - Manual (Page 7)

CALIBRATION STEPS
1. Power down the meter and remove it from its case. Turn off all offset and
span adjustment switches (S2-S10 down). S1 has no effect when zeroing
and can be in either position.
2. Turn the span control pot. fully counter-clockwise (20 turns max.).
3. Turn on a combination of span adjust switches (6-10) to obtain a total value
closest to (but not greater than) the SPAN PER VOLT desired (250 in this
example). The following chart gives an approximate span adjustment
value for each switch:
4. Place unit in its case and apply power. Apply zero volts. Adjust the
indicator to read zero using the offset adjustment pot.
5. Apply the SWING VOLTAGE (Vs) (4 V in this example) to the input. Set
the exact READOUT SPAN value (1000) with span adj. pot.
6. Apply zero volts to see if the zero value has shifted. If it has, re-zero with the
offset pot, then repeat Step 5.
7. After the span has been adjusted, set the signal voltage to the minimum level
(1 V in the example). Record the meter reading (in this example the reading
will be 250). Subtract the desired reading at minimum voltage value (0 in
the example) from the recorded reading (0-250 = - 250). Power down the
meter and remove it from its case. Set the offset add/subtract switch S1
(subtract = on), and the offset switches (S2-S5) to obtain a total value
closest to (but no more than) the difference between the desired reading at
minimum voltage value and the observed reading. The following chart
gives an approximate offset adjustment value for each switch:
Place the meter in its case and apply power. Using the offset adjust pot,
adjust the readout to equal the minimum voltage value (0 in the example).
8. Adjust the input signal voltage to its maximum value to see if the proper
readout is obtained (1000 @ 5 V in the example). If the readout is slightly
off, adjust the span pot to obtain the true reading. Then, recheck the reading
at the minimum input voltage (1 V) and readjust the offset pot if necessary.
Repeat the maximum and minimum readout adjustments until the unit
displays the proper readout at both extremes.
9. Set decimal points as desired using the three decimal point switches. The
unit can now be installed.
TROUBLESHOOTING
For further assistance, contact technical support at the appropriate company
numbers listed.
7
5.0 C
ALIBRATING THE
M
ETER
Direct calibration in the signal loop is usually not practical due to the
difficulty in varying the measured parameter and the confusing interaction that
occurs between span and offset adjustments. However, the PAXLPV can be
quickly and easily bench calibrated using a commercially available calibrator.
CALIBRATION PROCEDURE
The procedure outlined in the calibration steps below, minimizes span/offset
interaction and simplifies calibration. In Steps 1 to 4 the unit is “nulled” to zero
readout with zero input signal voltage. In Steps 5 and 6, the span adjustments
are made to establish the required slope of the transfer curve. Then in Step 7, the
transfer curve is shifted up or down as required by setting the offset adjustments.
In Step 8, the final “tweaking” adjustments are made at minimum and maximum
signal voltage. Setting the decimal points in Step 9 completes the calibration.
Before calibrating, the READOUT SPAN (Rs), SWING VOLTAGE (Vs), and
SPAN PER VOLT (Rs/Vs) must be determined.
WHERE:
Rs = (Max. Numerical Display) - (Min. Numerical Display) (Disregard Decimal Points)
Vs = (Voltage @ Max. Display) - (Voltage @ Min. Display)
Rs/Vs = READOUT SPAN (Rs)
SWING VOLTAGE (Vs)
Example:
Readout is to be 0.00 @ 1 V and 10.00 @ 5 V.
READOUT SPAN (Rs) = 1000 - 0 = 1000
SWING VOLTAGE (Vs) = 5 V - 1 V = 4 V
SPAN PER VOLT (Rs/Vs) = 1000 / 4 V = 250
SWITCH NUMBER SPAN VALUE
6 550
7 275
8 140
9 75
10 40
SWITCH NUMBER OFFSET VALUE
2 1400
3 700
4 350
5 175
LIMITED WARRANTY
The Company warrants the products it manufactures against defects in materials and workmanship for a period limited
to two years from the date of shipment, provided the products have been stored, handled, installed, and used under proper
conditions. The Company’s liability under this limited warranty shall extend only to the repair or replacement of a
defective product, at The Company’s option. The Company disclaims all liability for any affirmation, promise or
representation with respect to the products.
The customer agrees to hold Red Lion Controls harmless from, defend, and indemnify RLC against damages, claims,
and expenses arising out of subsequent sales of RLC products or products containing components manufactured by RLC
and based upon personal injuries, deaths, property damage, lost profits, and other matters which Buyer, its employees,
or sub-contractors are or may be to any extent liable, including without limitation penalties imposed by the Consumer
Product Safety Act (P.L. 92-573) and liability imposed upon any person pursuant to the Magnuson-Moss Warranty Act
(P.L. 93-637), as now in effect or as amended hereafter.
No warranties expressed or implied are created with respect to The Company’s products except those expressly
contained herein. The Customer acknowledges the disclaimers and limitations contained herein and relies on no other
warranties or affirmations.